I Think My Husband Got Roofied While At The Bar Last Night, Should I Take Legal Action If His Drug Test Pops Pos?

Good morning guys! So to start off, waking up with morning I’ve been laying in bed wondering why my husband wasn’t able to handle his liquor last night at the bar we went to last night with another buddy. Essentially, we had the same exact amount of drinks but I started to see signs that he wasn’t handling it well (stumbling, being super loud and clumsy, slurring his words) so I sat him down and I ordered him some food and water to help start to sober him up, but the PROBLEM was that next I seen how LARGE his pupils were, and I looked at every one else’s and our eyes were fine. To be fair, the lights were dimmed, but not enough for it to be super dark. Fast forward abt 20 minutes and I go to get him a glass of water and come back to him not being cognitive, throwing up, and bopping his head around. At this point I’m really scared for him so we take him outside, call a taxi, and head home. Since then (3am) he’s been doing the typical hang over symptoms, but he didn’t become cognitive again until after 5 am. I’m having him take a multi drug test to see if he will pop pos (I went and bought it this morning). If this test pops pos+, how do I go abt taking legal action?