I don't think it is a bug, just a confusion.
My opinion cleric stance shouldn't literally switch the stats, but instead just use the values from the other stat.
so basically while in cleric stance healing spells use int and damage spells use mind, instead of switching the stats.
Exactly, which is what makes this a bug.
Whoever coded the ability took the lazy way out and physically switched the stats when the ability is active, and then switched them back when the ability turns off. So you wind up with this problem where a permanent change to one of them is switched when the ability is cancelled. I am 100% sure that's what happened here, and it's a simple enough fix. But they need to know about it (how anyone missed it after all this time is a little troubling, frankly).
On a side note, the ability to respec these stats is essential. I'm sure they don't want players feeling they have ruined their character by making a permanent mistake.
I hate the entire idea of this stat allocation system, but yeah.. if they want to go ahead with it, you need to be able to change them so that rerolling isn't the only way to fix an error.