Goldenhorn attendee here. If my understanding is correct, GH staff already confirmed the attackers sprayed fire extinguishers. I don't think there is any evidence of actual tear gas.

If you haven't done so, get yourself tested for common date-rape drugs ASAP. You want to get tested before it's out of your system for good, sooner the better. Identifying the correct drug will probably be useful for both the investigation and prosecution.