I've noticed it in a few places/ways. In Netherstorm, in and out of the eco-domes. But I might expect that.

The one that made no sense, was just after I had tamed a ravager to learn Gore 8. There were no aggroed mobs after taming. This is frustrating because you cannot feed the angry new pet while in combat.

I put the pet on passive and feigned death. Still in combat. I ran far away. Still in combat. I was eventually able to dismiss the pet. Still in combat. More feign deaths. Still in combat. Finally I ran far, far, far away from the initial taming area and I finally I was out of combat. Nothing ever attacked this whole time. I can only assume I was in combat with my tamed pet.

I've found myself stranded in combat a couple times. It seemed like the best way out was to attack something else, and when that fight ended it would prompt the game to re-evaluate my status.

I have found a few spots where there will be a mob stuck in the ground trying to attack you, and it puts you in combat. But you can't see it and it doesn't hit you. The only way I figured out it was a mob was when I ran right over it it could hit me. I just had to run far away to get out of combat.

Actually had that bug happen a few times in the Barrens a long time ago, and more recently in Un'Goro Crater. A mob spawns in the terrain, aggros, and keeps you in combat.

Fortunately, hunters get a free "get out of combat" card. It still amuses me no end when I remember that kolkar wrangler stuck in a hillock near the Stagnant Oasis.

But, I did Feign Death... Multiple times...