Nice to see you back Chico
I know I'm arriving late to this but yeah, to me, it's not a bite.
First, it's not verbatim and while there's cases where people switch a few words around, usually they're not battle proficient enough to change the set-ups and they bite a couple lines, so it's easy to spot.
Also to me the only way to prove concept biting would be, to make a case that the battler has repeatedly stolen someone's concepts and incorporated it into their rhymes, otherwise there's too many battles where people can come up with the same concepts, but again it's in the continued coincidences where it gets dicey.