The striker went down easily which saw Fabian Schar sent off for the hosts. Brereton-Diaz's actions sparked a halftime brawl between the players.
Martin told the Daily Echo: "I just got asked there if Ben made a meal of it and all that stuff. He stands still and the guy leads with his head.
"You give someone an opportunity to make the most of it. I guarantee their players would have done the same.
"It's a moment of madness from their player. And it's the reason we have VAR, I'm pretty sure, is to overturn decisions if they're wrong.
"They've seen it back on numerous occasions in slow motion and that stuff. So it has to be a red card, I guess."
Toon boss Eddie Howe also said: "I think it's really harsh on Fabby, but I think we all know that you can't give the referee the possibility to even give the red card.
"That's something we (will) learn from. I think our discipline record has been really good for a long period of time.
"I don't think that's something that's in our game, but certainly a good one to learn from. I need to see it first (before appealing).
"I haven't actually seen a replay. Once we see that, we'll decide what we do. I don't want to be a cop-out, but I'd need to see it again before making a rash statement.
"I felt it was soft was my initial impression live. I thought that was really soft and it looks like Fabian's been caught out by a well-managed situation.
"But before I criticise any players involved, I'd need to see it again."