I've noticed that on the 2012 Halloween maps, that after losing a life and glowing for a while, a player is no longer affected by /watch.

Here you can see everyone but me is transparent (Except for the spawn area where people are standing inside each other):


After they've lost a life they appear as normal mice (Not transparent)


Forgot about this one:

mentioned this a while ago hue

+ if you lose a life, you show up as a normal brown mouse as well.
gets really annoying, especially since i depend on /watch to see myself.
not really easy to see yourself in a crowd of 30 identical mice.

This is what the industry likes to call a "No Fix".

Basically the bug is so minor and only effects a single map set in the game it's not worth the development time it would take to fix it. Development time cost money in staff hours, and with the bug only effecting 3 maps and will be gone soon with the event anyway it isn't worth the money to fix.