I think Melody that I wouldn't bother with the mentioning of it this time. She obviously knows. The next time though that you happen to find him in that position and not getting an answer on first tries I would quietly open the door, roll down the window if it is hot and turn off the car and ring the bell and let them know or if it is late put his keys in their mailbox. He may have to beat on his door or ring the bell a few times to get in but that is better than him coming to and driving off. Then the next morning just go over ring the bell and very calmly and keeping it brief say I put your husband's keys in the mailbox because I was concerned for his safety and the safety of others. Make his safety first so they will take less offense even if that is not really how we feel. Called soothing egos. Don't stick around, I am sure they will be embarrassed and do not want to confide and will appreciate your discretion.