This La Liga bullshit is ridiculous. It would be them breaching the rules, not PSG.
Btw. this has happened to Barcelona before. I mean it isn't, looking at the last few years, but looking at the past they've already lost two times their best players by other clubs triggering their release clauses. Ronaldo to Inter, Figo to Real and now Neymar to PSG. It was a long time ago but I don't remember that ever happening to Real.
Also, when I think about it, maybe Barcelona will go for Hazard. Left wing, would suit Barcelona style and most importantly, he's the only one who is such a prick that is capable to force the transfer in an ugly way.