So, I was originally making this bug report regarding enemy players being able to use the Holiday Punch to stun friendly users with laughing, which still is an issue, but I stumbled across a far more important exploit when testing out the new friendly plugin. If a friendly user stands in the middle of the invisible barrier of the spawn entrance/exit and an enemy walks into them, the enemy can phase completely through the barrier and end up on the inside of the spawn.
It's exactly just that easy.
Mid-post edit: For some reason the thread just randomly saved there... ♥♥♥♥ed up my title :/
Here's a demo showing it happening. It's fairly easy to pull off, seemingly.