The Irishmen scored eight tries as they hammered the Warriors 46-22 at the Royal Dublin Showground.
"I suppose you could say we showed some good spirit in the second half, scoring two final tries ourselves in the closing minutes and limiting them to just three scores after a first half that was fairly embarrassing," he said in The Times.
"Some of our guys put in some good individual performances and I thought Kevin Tkachuk was outstanding with his ball-carrying but that's about it. Those kind of things are merely a few bright spots in a pretty dark day. The whole competition has been extremely disappointing for us, but at least we have one more game to look forward to, against Bourgoin next Sunday."
JP didn't mince his words about the result which means Glasgow have now gone 13 Heineken Cup matches without a win.
"It was an embarrassment and we actually escaped lightly," was the brutally honest verdict of JP in The Scotsman.
"We had talked all week about building on our strong performance at Ulster, but in the first half we were an embarrassment. Basically, we didn't turn up until the start of the second half, but by then it was far too late.
"Obviously Leinster had a lot more to play for qualification wise, but there was absolutely no reason for us to be nervous about facing them."
The Glasgow skipper says in the Daily Record: "I could maybe accept losing like that if we were a crap side.
"But we ARE sometimes a decent team which makes this defeat harder to handle. In the first half we were an embarrassment."