[tipperdog]

There is no question that SB thought he was calling an all-in bet, correct? Given that fact, killing his hand would be perverse even if the "letter" of the rule says his hand should die (and I don't think the letter of rule so states).
TDs must exercise common sense!

I would say that action is now to the BB, who can call or fold for the remaining T175. I would also give a warning to SB for exposing his hand AND give a warning to BB for keeping "mixed stacks" that result in this kind of problem. Players must keep their stacks tidy.