Aislyria
Well...you see them sitting next to him after Tohru transforms him after he leapt out of the classroom window his first day of school...and he didn't turn back into his other form when he didn't have them on right away when Shishou had them. I think the actual 'cat' transformation makes the third transformation halt for a little bit.
He does change back to human after awhile when he's in that form...so..I imagine there is something like a 'window of triggering' once he first turns back to human.
When he's in what form?]
Yes but that only happens in the first volume. In volume five when they're at the lake house he changes back wearing his beads. The first volume is the only time you see him with the beads off. Also considering that doesn't occur in the anime also its likely the first volume change was a flaw. The anime was made at the 8th volume so its highly likely the change was corrected for the anime.
I just found yet another flaw in the anime. In the first ep Kyo isn't wearing any beads.