Yes, I have heard of cases in which young men in seminary fall in love and hence leave seminary. That a young man -- or more likely a bit of an older man, after all of seminary in done and through -- would fall in love while a priest seems to be largely unlikely, since "falling in love" involves some kind of special relationship with a woman that develops over time. Infatuation might befall one suddenly, but falling in love is a process within a relationship. Priests are not in the position to pursue such relationships, even accidentally or indirectly, in nearly all cases. I don't think the Church should drop the celibacy vow as a necessary provision across the board to accommodate a few special cases. More reasonably, it seems to me, celibacy should remain a necessary vow, and special exceptions could be made, as they already have been made, for Eastern Rite priests, for example.