Its marginal call, but he is just about priced in. He is getting 3/2 for his money and he is 2/3 to hit and win if, and its a big IF, he has BB only on one pair.
I wonder if BB would have been so upset if say SB had called on Nut flush draw?!?! (because of course he has more outs if his read is right here ;-) )
At the end of the day BB should be happy, he"s got his chips whilst ahead. If he is going to get that upset at losing a 60/40 shot then perhaps he should rethink how much he wants to play poker, because he has a lot of heartache to come, lol.