[Alchemist]

Since it was folded to Andy and with only a 7, Q, and the BI left, I'd say it's reasonable to put him on a semi-steal. 4th street worked out perfect for you by catching another low and him a brick enabling you to easily bet him off his hand. But I'm not sure if the risk/reward ratio is worth defending your BI here considering the more likely scenarios that would arise on 4th requiring you to fold your hand.

I suppose it comes down to how aggressively you want to play. Myself, I try to avoid potentially tricky situations--especially in a tournament. Just my opinion.