He was antagonizing a man, very, very badly. Picking at something sensitive he should not have been picking at. He had been warned, several times, and he ignored those warnings.

[Then, because this probably needs clarification, he adds:]

It wasn't me, but I did know it was gonna happen, and I did arm the killer.

[He's not confessing out of guilt, but because Kesara deserves to know as much of the full story as he can give. He's not going to tell her Royce did it - though he's hoping Royce will tell her himself - and he's not going to tell her exactly what picking at something sensitive entailed, but everything else is fair game.]