Endermen teleport psychotically when on fire / during rain

Additionally, (and I guess this is the real bug) if they are killed while on fire, they'll still attempt to teleport and their body (along with their exp) will be teleported to their 'chosen' location.

Steps to reproduce:
1a. Whack an enderman with a sword that has fire aspect.
1b. Set fire to the surface it's standing on.
1c. Coerce it into walking into lava
1d. (To a lesser extent) Shoot it with a flame bow