Nick Diaz says Conor McGregor HIT A KID in his water bottle throwing rampage at the UFC 202 press conference ... and even got an exclusive interview with the alleged victim.
Nick was standing right next to his brother when Conor launched the water attack -- and after the incident, he grabbed the pint-sized alleged victim for a video testimony.
"Aw, that's f***ed up," Diaz said.
"Bro, why you hitting kids with bottles??"
So far, no word back from Conor.