Oh? Really? [That tone speaks of familiarity rather than confusion, oddly enough. Ah well.]

At the moment, I can't be sure; heart swap only lasts a limited amount of time on pokemon- a few moments actually- but on humans... [Hnnnn...]

I would guess that even if it was permanent, the source would get word of the issue and rectify it with a second go- it's not too difficult in that regard, particularly if the phione are acting as target points, [he adds with a look toward Bill's own.]