It's a suuuuper brief appearance, so it's not a huge deal one way or another if it's "canon" for us-- it wasn't even in either of their books but in a Hitman issue instead.

http://scans-daily.dreamwidth.org/2206425.html?thread=73940953

Basically Catwoman stole a magic gun, Jason was called in by Tommy to tell them about it.

Really up to you!