[CRASH] Mac client - Start Garry's Mod on the same network as League. League crashes.

We have two computers attached to the same network. If I'm in a game, and the other computer connects to a garry's mod server, the game will crash.

Steps to repeat:

1. Start a game of league of legends. If you're like me, you'll be in your promos.
2. Enjoy the game! Hell, you'll probably be winning. Your team will be complimenting you on a job well done.
3. Ooooo... spot an enemy attempting to run away. Said enemy will have just a little more health than Morgana's Q is going to do, but don't worry, you'll surely get the kill with the follow up W or an autoattack should do.
4. Immediately as you're casting your Q, have someone in your house attempt to connect to a Garry's mod server, so they can get do some my little pony role play bullsh*t or whatever they do.
5. Game will crash. Bugsplat will come up.
6. Promos.
7. Attempt to reconnect for at least 5 minutes.
8. Finally reconnect, and find the enemy team at your nexus turrets, and your team threatening to report you.

This happens EVERY SINGLE TIME. If I get a bugsplat message, I immediately check to see if anyone in the house is playing Garry's mod... and EVERY GODDAMN TIME.

So, I think there's something going on at the network level... I have no idea.

I've attached the error log that was generated, just in case that's helpful.