Must a SB sized allin postflop bet be completed to the size of the BB?

[Rick Nebiolo]

Quick one and maybe not even mildly interesting compared to Randy's and some other posts. I wasn't in the hand (I folded BTF) but would have ruled it differently than a few other players who were adamant they were right.

Game is NL with 5-10 blinds. Post flop a player lead bets all-in for $5. Next player (with lots of chips) calls the $5.

A player speaks up and says "Hey, you need to make it $10. Ten dollars is the size of the big blind and the minimum bet when you have chips."

Was the player who spoke up correct?

~ Rick