This is an interesting question, because I would suggest that you need to ask whether the Czechs saw themselves as Germans or Czechs, rather than did Germans see Czechs as Germans or Czech.

In the period 1815-1870 Bohemia, the land of the Czechs, was part of first the Austrian Empire and later the Austo-Hungarian Empire. Napoleon's nationalistic stirrings during his attempt to deal with the Austrian Empire inspired Czech nationalism, and in the 1815-1848 period there was a sustained effort to establish a Czech written culture to counter the pressures of German as the dominat langauage of the German centric Austrian court. Czech (as well as Slovenian and Hungarian) linguistic and cultural traditions were increasingly used as poltical tools by educated elites who desired more local controls, all the while Metternich tried in vein to suppress nationalism and liberalism.

The Czech elites saw themselves as part of the pan-Slavic movement, and 1848 hosted the pan-slavic convention, which was broken up after the failed 1848 revolution. However, this idea of pan-Slavism was more a nationalistic notion rather than an outright declaration of slavism by the Czech elites, for many within Bohemia spoke German and were closer culturally to Austria and the neighbouring Germanies. Post-1860 when Prussia set the final pieces in play for the unification of the Germanies there was a desire to bring Austria and Bohemia into the united Reich, but after Prussia defeated Austria in 1866 the Prussians decided against annexing Bohemia and settled for hegamonic superiority over the Germanic states. This was the deathknell for any hope of Germanic Bohemians being brought into the Second Reich when it was declared in 1871.

With the creation of dual monarchy of Austro-Hungary in 1867 came an ever increasing tension within the empire between its various nationalistic elements, with national identity becoming a source of political power and capital exploited by local politicians. The idea of slav or german was very much a poltical fiction up until it was not, as those destinctions were labels used by politcians to drive their own power bases within the empire. It was also used by the Vienna government as a means of plecating local populations within the disperate empire, allowing local languages to be used in the army, the civil service, and churches. Indeed, part of the 1867 compromise was that Hungarian and Czech would be the first languages of the regiments raised within their territories.

So, to answer your question, it would depend on which Czechs and which Germans you spoke to in which time period. Some Czechs, especially the educated and elites, viewed themselves as Czech and slavic as counterpoint to the German hegenomy. Most Germans, on the otherhand, propably did not really think about it other than to see the drive for Czech culture as odd and counter-productive (why speak Czech when German was the language of court and civil society). Slavic nationalism arose to counter German hegenomy, both within Austria and the emerging Second Reich, and by 1871 there was a much clearer deliniation between Czech Slavism and Czech Germanic cultures. This in turn would poison the well after 1918 and lead to the Sudetenland crisis in the 1930s because 'ethnic' Germans were a minority within the boarders of Czechoslovakia. Germans likely saw Czechs as both Germans and Slavs depending on which language they spoke, where they were born, and which culture they expressed.