Attached crash report
Was it a bug to spawn a witch in a temple ? Possibly. Why not let Mojang answer that.
The situation has not changed in 1.6.4
Previously to 1.6.2 a witch is a valid entity to spawn on a block which exists in a structure, and in a swamp biome, providing it meets the other spawning criteria (bounding box, light level etc). So if a portion of a desert or jungle temple (which share the same parent class which contains the code) is in a swamp biome, then it is possible for a witch to spawn there.
@Th3F4114n0n3 witches have always been able to spawn in any structure in a swamp biome. It was not a bug in 1.6.2. If it is a bug it goes right back to the scary Halloween update when witches were introduced.
The description asks a legitimate question, did 1.6.3 fix a bug in 1.6.2. Or is there a bug in 1.6.3
Well in my defense I logged this bug a long long long time ago, and my observations were based on playing the game. Now that I see your explanation and video and look at the code, I have corrected the "errors" in my bug description.
I can also confirm this issue. I had 16 pens of sheep. I wouldn't breed the pens right next to each other at the same time (to keep the sheep from breeding with different color sheep), when I breeded two collections of sheep they could be pretty far apart, the next sheep born would occasionally be the wrong color. I've attached a screenshot of the result after it happened a couple of times.
I can confirm the the LC parameter is inconsistent. I logged in to my SMP server today and the LC parameter of a chunk that used to be 47 is not back to 79 again. Even though there has been nothing built in that chunk at all. Very weird behavior.
Works correctly in 1.4.7 (full release). Fails on snapshot 13w01a.
Resolved in 14w34d