I don't think anyone has to play a perfect or near perfect game to win unanimously, they just need to have played the best game. My issue with Adam winning in general (and me hating him win unanimously) is that I feel like he did not play as good as a social game as Hannah did.
Early in the merge, Hannah made moves to control her own game by flipping on Zeke as she felt Zeke was too controlling and a large threat. Whereas Adam was faulted early in the game as being paranoid and not being able to come to a decision. Also, Adam unnecessarily played his idol on another player, completely wasting it.
Also later in the game, Hannah made the decision to eliminate Sunday and Bret. Even though it may have been perceived at the time as the "wrong move" because threats were not taken out then, she was still able to make it to the Final 3 without the "main threats" being in the game. I felt like Adam / the jury are incorrect in saying Hannah made bad moves when her moves worked out.
The only moves Adam could be credited for in my opinion was targeting Will and finding an Idol in F5 to avoid the votes being played on him, but this far under-performs Hannah IMO.
I think Adam won because Bret was bitter that he was targeted before David went home, and was able to convince his other Gen X Friends that Adam was playing a good game. Also, I feel like Adam's game was more visible to the Jury than Hannah's game. This is probably why jurors were set on voting Adam before the FTC. Because of these things, when Hannah slayed the FTC and was trying to explain her game, it landed on deaf ears.
I thought Hannah deserved to win, and I was upset that Adam was given the victory by the Jury