[AA suited]

SB had Ah Qd?

i thought you said he was a tight ABC player?

2 overcards and 2 backdoor draws (straight + flush) = ~8outs, which is 5:1. your 1/2pot bet is only giving him 3:1

I would not say a person who calls a 1/2 pot bet w/just 2 overcards and a backdoor draw as being tight ABC player, especially when someone is already all in.