Medication Error/Unruly DON

I worked this past Sunday from what was suppose to be 7-11pm turned into 7-1am. I work in long term skilled care facility. Well...at 8pm my DON calls to ask if i could stay any later because the person that was scheduled could not come in for the 11-7 shift, so my DON was left to do it, but she did not want to. I told her that i could not stay any later at the time she called. Then she calls back an hour later saying she went to a get together (party) and had been driving around for an hour looking for gas. (This area has not been hit that hard regarding gas shortages)...anyways...she says that i am just "stuck" and have no choice as if she was telling me i had to stay until 7am. What could i do? Nothing. Say i was leaving and loose my license? No! So i called my DON's boss, the Executive Director to settle the problem. My DON ended up coming in at 12:15 am. My question is...there was a med due at 12am, neither I nor my DON gave it. She is filling out a med error due to it and probally will blame it on me. Neither her or I ever work 11-7 shift, I charted the hour i worked over while waiting on her. Who is at fault? Also...does anyone else have a difficult DON that they deal with? Sorry for ranting...maybe it's time i look for another job. I love my patients and my co-worker's but The DON is just not the person I want to work for. Are all bosses like this?