The entire premise of this thread is absurd.
OP is seeing what he wants to see, that’s all this is.
There is literally no evidence of Dak “looking concerned” or whatever on the sidelines.
Like absolutely none.
Other than OP’s “just trust me bro, I could see it in his face”. LOL
There is no hard evidence but I wouldn't say the premise is absurd.
Looking at the big picture it is easy to make a case that it is certainly possible Dak is hearing footsteps. I'm not saying he is, just that it is certainly possible for tangible reasons. I would prefer he does get a little nervous. That's would be a good thing for everyone.
But yea, in his head he is dealing with the unprecedented criticism he is getting from multiple directions, fans throwing things at him as he exits the field, the not very good recent history of his play ("slump", 49's, opening week 22). It should be expected he would get a little nervous watching the team succeed and rally around the backup QB. He's been that backup QB multiple times himself and he knows as well as anyone how things can go.
I have no idea what he was thinking on the sidelines but some anxiety about his place wouldn't be out of the question. It might even be expected.