I don't know, I feel like the way it collapsed looks very realistic. The part that makes me think it's AI is the people; if you look closely there appears to be a tiny bit of weirdness in how they move, but more importantly, the fact that none of them turn around to run even as the building collapses on them.
Bro! He didn't spurn her, he politely rejected her because he loved Arwen more and he had WAY bigger things to worry about. He received her flirtations gracefully but didn't lead her on.