I live-video recorded, it shows me aiming ahead, at the same time while recording a demo... In the demo, it shows me waaay behind. I even got killed by a marauder about 8 metres away! (for those mappers, ~200 units)
Another evidence is that if you play on a high ping server with unlagged, for me it is every server except SIR server, if you fire the lucifer cannon while a dretch is close up to you, i have to either turn around and shoot infront of me (splashes happen with lag for some reason in gpp, in 1.1, the bullet just fires later), or i shoot DIRECTLY at the dretch. Otherwise, the dretch will 'walk over' the bullet and my bullet exploding two thirds of a second later on my screen. This is one reason why i don't use lucifer cannon anymore.
When you play the demo on the other hand, it looks perfectly normal, seems like you shot the lucifer cannon and it warps in a way...
I can also prove the same thing for the adv goon, as in the demo i fire 'too behind'.
I'm sorry if I bother your life too much.