Mackems defender Collins was fuming and said even the Newcastle players had admitted it was a dive.
Collins said: "I just saw the penalty decision on TV. It's a terrible decision to be honest. Steed sort of stumbled over himself Stevie (Taylor) has gone on another yard and then fallen over.
"Damien Duff got booked for diving and he himself said to me 'It was a worse dive than mine'. He actually said that to me. Perhaps the fact it was a few minutes after the Duff incident swayed him a little bit.
"The referee gave one or two things that were a bit soft in the second half."
Collins insisted Webb had got it wrong and added: "The linesman is on that side and that is where he needs to help the ref out.
"He didn't actually flag. I think he has radioed it into the ref and said it's a pen.
"I said to the linesman afterwards, 'How come you never flagged?' and he said he radioed it to the ref.
"I accepted it at the time because there's a lot of bodies there and I couldn't really see it. But I have since seen it on TV."