So there's not a whole lot of information out there on Trevisan, or what he did during the battle. Nicolò Barbaro, a venetian physician whose diary is the most complete venetian perspective of the siege, offers the most color and cites Trevisan as present in deliberations among the Venetian leadership, and also mentions a few naval raids conducted by Trevisan against the Ottoman blockade. Lack of additional information on Trevisan's role in the fighting is probably due to the fact that the galleys he commanded were seriously damaged in a naval skirmish on the Golden Horn around April 28th, a month before the most intense and decisive sequence of fighting began. On May 13th Trevisan's sailors abandoned their remaining ships and worked to repair the walls (by then heavily damaged by bombard fire) and Nicolò Barbaro then goes on to list Trevisan among the captured Venetians presumably fallen prisoner sometime in the final assault. Trevisan is also listed by Barbaro among the post-battle casualties, and thus he was probably either executed or died in captivity (Barbaro composes several lists of venetian notables involved in the battle, and Trevisan appears in the list titled "Questi si son nobeli morti, da poi la prexa de la zitade de Costantinopoli" translatable as more or less by, "These are the noblemen who died after the capture of the city of Constantinople").

So unfortunately, our Trevisan (whose name is rendered by Barbaro as "Cabriel Trivixan") did not escape the Sultan's soldiers. Most of the Venetians who did escape were non-combatants, like Barbaro (a physician), who in the final stage of the siege took refuge in Galata (cut off from the city across the Golden Horn and relatively unaffected by the fighting) and were able to escape to Venetian or Genoese possessions in the Agean by sea. Others were allowed to leave Galata after negotiating with the Ottomans.

Many Venetians and Genoese ha pledged to defend Constantinople to the end, and Trevisan was one of these; Barbaro cites Trevisan as one of those among the Venetian leaders who pledged not to flee, even though they could very well have packed up their galleys with the remaining Venetians in the city and abandoned the cause.