Yep, it sounds like the audio drum loops have fills, or at least pickups, at the ends of loops. Pretty dumb, IMO. That's what the FILLS are for. Lots of 16 bar blues out there, and if the loop is twelve bars AND puts a big pickup in, you just lost the usefulness of the style.
Korg tend to do the same thing with their longer pattern styles, but at least it's fairly subtle. A roll (if I have got you right on that) is hardly what I'd call subtle!
But this does reinforce one of my main objections to going the audio route. On a MIDI style, this roll would be child's play to remove. On an audio style, not so much (if at all). You gain a lot with audio. But you also lose a lot, and put yourself at the mercy of the style creator. If it isn't PERFECT for you, forget about editing it to be perfect...
_________________________
An arranger is just a tool. What matters is what you build with it..!