[MrWong]

Originally Posted by chuff me dizzy

Urban meaning of a knacker .......... knacker
Incestuous, boxing, sovereign ring wearing, tracksuited shaven headed scumbags. Girls wear bellytops (Even if they're 15 stone), guys are small, jewelry and violence are rampant. Enjoy having children with sisters, looking at you with squinty eyes and scaring people. In many places refers to SCUMBAGS in general, and good travellers are not covered by the word - depening where you're from.
"C'mear yow, give oos a fooking Yaro boss or I'll fooking box ya" said the knacker.
And by God, Marcs spot on with that one !!!!!!!

From that description it sounds like Marc's a knacker.

It's like projection, he attacks someone for something that he is.

It's like when he calls Harry out for having a showmance for airtime when he's doing the same thing with Sam.

Or when he calls Harry out for getting naked when he does it too.