Ok so after losing both of my lvl 85 pets today, one vanishing from my active list, the other getting the bugged rez problem from HoO, I spent about 30min trying different ways to rez the pet, and I finally managed to unbug him. Here's what I did:
1. Put all pets into the stables
2. Put one pet into your 5 active, and call the pet out.
3. Put the pet back in your stables. Do not dismiss the pet.
4. Put the bugged pet in the exact same active spot the previous pet just had.
5. Try to resurrect the bugged pet.
This just worked for me, and I think it's because when you call out the pet and stable it, and replace it with another pet from the stables, it would normally automatically call that new pet out, making it the active pet. By that mechanic, it makes your bugged pet active, and therefore rez-able.
Hope this works for everyone else until Blizz fixes the problem
Also be sure to log out after fixing the pet, or it may re-bug as I just had happen lol
