I'd imagine the drumming in all of their songs is some drumming by the Rev, as he was their drummer.

Quote from MAGGOT :

I'd imagine the drumming in all of their songs is some drumming by the Rev, as he was their drummer.

The phrase, "That's some drumming..." is a description of how good The Rev's drumming is

Yeah, he truelly were great. Avenged Sevenfold usually plays rather strange rythms, but their drummer made it sound good and had full controll on it.
I do hope Avenged Sevenfold continue making music, and get a new drummer, tho of course... they most likely will take a brake for some time now.