"That's goo--AHH!" When Greg goes down, Natsu just shouts in alarm. Yeah, this guy is definitely not okay. Where'd he even hit him? His head? Hopefully not his head, that would be really dangerous. Can you die from getting hit with a rubber ball? Is he dead?

The ball bounces off the bottom of the stall and harmlessly rolls away behind them, completely ignored at this point by the panicked dragonslayer who's now crouched over the other patron, trying his best to not have a mental breakdown.

"Uhh. Are you sure you're okay, mister?"