I think he means it went straight down while in the roll.
This bit of info speaks volumes. It tells me he was probably in an aileron roll, not a barrel roll.
that he didnt add a touch of nose up before he started the manuver,that once the aircraft started to roll didnt add any down elevator to keep the aircraft nose from falling.
Lastly could benefit greatly from a couple of hours with an instructor.
Or then again i could have read it all wrong....in that case disregard