At the end of the stalemate between Arsenal and Liverpool, Bradley went down on the pitch with what was later confirmed a serious knee injury.
At the time, Martinelli tried to drag Bradley off the pitch and also kicked the ball at him believing the Ulsterman was wasting time.
The Brazilian and Bradley later exchanged messages, with Martinelli apologising to his opponent. But that didn't stop Neville attacking the Arsenal player, branding him "disgraceful".
Keown said on talkSPORT: "Just trying to inflame the situation when he's (Neville) got nothing else to do in the commentary position.
"He was bored, it wasn't a great game. He was making that the narrative."
Keown added: "Gabriel Martinelli is one of the nicest people I've met in football. He's very courteous, he speaks to me on the touchline.
"When I saw what was happening, I thought it was a misinterpretation from himself.
"(Jeremie) Frimpong was on the floor two or three times, the ball was begging to be put out of play, Arsenal didn't do that.
"It just had this sort of tetchiness around the game and he misread that. He made his apology and an awful lot was made from it."