Gyms are broken

Impossible to defeat a Gyms Snorlax, where it would drop to 0 CP & get kicked out of the gym. The game just gives it infinite HP instead, making it impossible to take over any Gyms that have a Snorlax in them. Chances are this may be the case with other Pokemon and/or Gyms.

DJ A. Vactaire about Pokémon GO, v1.37.2