crazy urgoz lag question

ok so ive been in urgoz before and didnt lag, so its not the amount of monsters.

My laptop is fairly powerful too.

But I was in a Cryway pug, and all of a sudden, My BiP stopped working, i couldnt activate skills, BUT i could still walk around and see what everyone was typing (usually yelling at mr BiP for being afk which i wasnt >_<) I didnt blame anyone, i just left after a while of nothing since i was of no help, they got another BiP and went ahead. I dont blame them.

My question is, I NEVER lagged like that eVER on my laptop. I Suspected someone in the party might have caused it (not intentionally of course) but I have no idea. Then i thought maybe the constant spam of BiP might have overloaded my end of the connection or soemthign? But then i tested it and i could spam it fine without lagging out.

So....um....yeah...