Shit, bet he fucking jumped out his skin when that went off, I had one delivered from Ireland a few months ago turned up no problem, guess it's luck of the draw
I had a similar problem once, try tightening the pipes abit more, I swore mine were all tight and not leaking but after another round of tightening them all up it was fine
have alook at the powerflow website and find one of their closest fitting centres as they custom make them in the garages, so they could take your silencer out if you ask nicely