I think I would look at this picture longer if your roller accidently "kicked" her crotch... don't they have this kind of accidents when doing this kinda "fun" activity?
"Live fast, die young, leave a good looking corpse." - John Derek, Knock on any Door 1949
It may happen during practice, but I would be really embarrassed if that happen to me during competition. A skater would have to be really bad and out of position for an accident like that to happen.
The only time I've seen an accident like this happen is during public dance night. That's when the rink is open to the public and they have an organist playing dance selections. The rink is more crowded than during a competition, and the public skaters may not always skate the pattern correctly. Hence two people may bump into each other in such a way that their wheel touch and stop turning long enough to throw them off balance and lose control.