Joel Edgerton as Sam Carter in The Thing (2011) is found to be infected at the end as Kate burns him with the blowtorch, but was he really infected? When Kate burns him he doesn't seem to burn like an alien. It leaves a kind of mystery for me whether he was really infected or not.
Yes, Carter is infected. Here is the relevant snippet of an interview with one of the screenwriters, Eric Heisserer (warning! there is a spoiler about Kate's fate as well):
“Carter turns [into The Thing] in the spaceship. I think they may have vacuumed out a lot of the air from those moments. Moments where they were separate long enough for that to happen. And as Kate is killing The Thing, Carter realizes it’s too late to save the other version of himself from being blown up, so the best he can do is try to survive himself and get back and occupy her.”
It seems like there is no uncertainty (although it can be that the on-screen depiction is a bit uncertain as it sometimes is in contrast to how things are planned out). From Wikipedia:
As Kate and Carter return to their vehicle, Kate notices something strange. She accuses Carter of being a Thing because he is missing his earring. When she confronts him, Carter points to the wrong ear and Kate then burns him in the cabin of their vehicle, during which he screams like the Thing, proving Kate's deduction correct.
I'm late, but I also think that there's another option here, where The Thing will infect a host body without taking control. I feel like they kind of suggest this in the scene where Kate is looking at their fillings, particularly with the bearded guy (because he's pretty nervous, and you would know whether or not you had fillings). Perhaps they're suggesting that you can't even trust yourself, for fear of it infecting you without you even knowing it. Anyway, that leads me to suspect that while Carter was The Thing at the end, he wasn't aware of it.