I wish I could fully answer this question but I can only point you to sources...

Firstly, I've answered a question about theft in the Americas and I cited that mexicolore article which is the source of that TIL post. In general, I'd say mexicolore is one of the better sites on the internet about Aztec/Nahua history. But, it's also a collection of articles by other authors, and so each must be evaluated on their own merits. The article cited is by Warwick Bray, and the sources he cites are his own book, The Everyday Life of the Aztecs, p. 83-87, and The Aztecs by R. F. Townsend (2000), p. 91-93. Mexicolore also includes this article, The Aztec Legal System, by Z. Saadia which adds more information.

Though I love mexicolore, an even more comprehensive source on both Aztec and Mayan law is a series of articles at the Tarlton Law Library. These in-depth articles rely on a couple of sources: Handbook to Life in the Aztec World by M. Aguilar-Moreno, Law and the Transformation of Aztec Culture, 1500-1700 by S. Kellogg, Law and Politics in Aztec Texcoco, by J. A. Offner, Aztec Law by J. M. Seus, The Aztecs by M. E. Smith, and An Overview of the Legal System of the Aztec Empire by F. Avalos. They also cite Carter (1964) of which I cannot find further info (not everything is on the internet I guess). These books and articles all appear to be reputable sources, and I love Michael E. Smith's The Aztecs...but in the end, whether we're writing a book or an askhistorians answer, we're all relying on the same 16th/17th century documents. The Tarlton Law Library article Aztec Legal System and Sources of Law mentions those three sources of Aztec law: The Florentine, Mendoza, and Libro de Oro (Ixtlilxochitl) codices. In the article, Strategies of Legitimization and the Aztec State by D. V. Kurtz (http://www.latinamericanstudies.org/aztecs/aztec-state.pdf) he says,

Nobles were tried in special courts and the for the same offense a noble was punished more severely than a commoner; with greater privilege went greater responsibility (Berdan 1982:49; George 1961; Sahagun 1950-1969, Book 8:41).

So it seems the original source of this claim is from Sahagun. In the wonderfully relevant paper, Living on the edge in an ancient imperial world: Aztec crime and deviance, by Frances Berdan, Berdan adds some details also citing Sahagun's Florentine Codex:

Penalties for drunkenness depended somewhat on one’s social status: nobles and priests were summarily strangled, while commoners were only strangled for their second offense. For their first violation, they were either [shaven], enslaved and/or had their houses torn down. The general idea reinforced by these different penalties was that drunkenness entailed more critical consequences for nobles and those with heavy public and religious responsibilities.

As in my post about theft in the Americas in general; the same moral ethos was held in the Incan empire - nobles and bureaucrats were held to a higher standard than commoners because their actions held more social impact for the functioning of society. For the Inca, if a commoner stole bread they were punished. But the local administrator was punished more so, because it was their job to make sure that farmer lived well enough so that theft wasn't even considered to begin with. So if it did occur, then the greater responsibility fell on the noble. The commoner, of course, was just hungry or trying to feed their family.

But of course, this is only what is written, and reality is often messier. As in all ancient and modern societies with severe class/wealth distinctions, and if they have a court system which requires self-advocacy...there is bound to be shenanigans.

Aztec nobles may have been tried in separate courts, but they knew the law and rhetoric and could defend themselves (as there were no professional lawyers). While commoners were bound by law to not have such information; yet at the same time, they were still required to represent themselves (or have a friend represent them) in the lower courts. As you could probably assume, this system only seems fair if you do not add the human element.

There are so many ancient and modern societies who had/have egalitarian legal provisions, from Roman law to the United States, even the 1936 Stalinist constitution of the USSR held itself to similar standards. Yet in all those societies, the law on paper turned out to be just as ephemeral as those documents themselves.

There are so many statements throughout ancient history that touch on this point, let's look at bronze age Mesopotamia. It's common knowledge that this was one of the earliest ancient societies to have a court system filled by trained functionaries providing the service of a public legal system, and what do proverbs say about this system?

If somebody is caught, he will always be released the first time.^1

It is easy to think of the "advanced" societies of the bronze age and marvel at their temples, their bureaucracy, and their legal system...But for people living in that society, the reality was parents had to write proverbs to instruct their children to always remember it's flawed. In many proverbs the legal system, debt, and poverty are often conflated.

Wealth is hard to come by, but poverty is always at hand.^2

The poor are the silent ones of the land.^2

All the households of the poor are not equally submissive.^2

How lowly is the poor man! A mill [for him is] the edge of the oven, his ripped garment will not be mended, what he has lost will not be sought for, the poor man - by debts is he brought low, what is snatched out of his mouth must repay debts.^3

Many proverbs mention "the fox," a term for a bully, trickster, or in common parlance, an asshole; yet in one proverb the fox and an overzealous litigant are compared and it's difficult to tell if one is put in a better light than another - perhaps they are shown side by side because they are one in the same...

The fox had a stick with him, [he asked] 'Whom shall I hit?' He [who] carried a legal document with him, [he asked] 'What can I challenge?'^4

Perhaps we can feel the anger in some proverbs which only hint at the unjust reality that average people lived through...

He is fortunate in everything, since he wears a [fine] garment.^4

The most explicit example of proverbial anti-legalism is from the early bronze age Mesopotamian text, The Instructions of Shurrupak. Two of the proverbs mention the legal system and both of them say, more or less, just don't get involved at all...

You should not vouch [in a court case] for someone, that man will have a hold on you. And [for] you yourself, you should not let somebody vouch for you, (one manuscript adds) that man will despise you.^5

You should not loiter around where there's a fight, you should not let the fight make you a witness. You should not let yourself...[get dragged into] in a quarrel. You should not cause a quarrel...^5

The (much) later Hebrew text Proverbs continues on the theme. Sometimes they use the same phrasing as earlier bronze age proverbs, the most striking in my opinion is one about ants (30:24-25) which is nearly the same in a bronze age proverb cited by Yoram Cohen, *"Four things there are which are smallest on earth, yet wise beyond wisest. Ants, a people with no strength, prepare their store of food in the summer."*^1 Suggesting that at least some of these proverbs may have been inherited from bronze age Mesopotamians (along with many other parts of the Tanakh).

If a wise man goes to court with a fool, there will be raving and laughing with no resolution. (29:9)

Even what you have seen with your own eyes, do not bring [it] hastily to court. Otherwise, what will you do in the end when your neighbor puts you to shame? Argue your case with your neighbor without betraying another's confidence, lest the one who hears may disgrace you, and your infamy [will] never go away. (25:7-10)

Do not be one who shakes hands in pledge or puts up security for debts, if you lack the means to pay, your very bed will be snatched from you. (22:26-27, also see 6:1-5 and 11:15)

The passerby who meddles in a fight not his own is like someone who grabs a dog by the ears. [And] like a madman shooting firebrands and deadly arrows, is the man who tricks his neighbor and says, 'I was only joking!' (26:17-19)