AITA For Being Annoyed at Work Friend's Music Taste?

Dude,

So, I got a friend at work that is a lot of fun. We have a lot in common. We got hired on at the same time. I feel comfortable around them for the most part. (I'm trans, fyi) I always thought of them as a good person. The friend got injured at work. They were taken to the hospital and treated. I stayed late to help pick up the slack even though I said earlier in the day prior to their injury that I could not stay that day for overtime. I figured with the circumstances, I could help out the work team. So my friend is off for a week in relation to the injury. I volunteer to move to my friend's shift to help with the additional loss of personnel. On my friend's first day back from time off to recover, they tell us that they are leaving early to see a concert and made it clear that they were determined to see the concert. The concert in question... Santana and The Doobie Brothers. (Yeah. The effing Doobie Brothers, dog.) I was speechless. Like, dude. Myself and our department are busting our butts to keep up with a personnel shortage. We are all making sacrifices to get goals met at work and homie has just gotta see some mid band from the 60's. Like if this was the Eras Tour, or Kendrick, or something ok. Also, homie is supposed to be resting. it doesn't look good to be limping around work and then leaving to hit up the local amphitheater to listen to music you hear in a CVS. I love my friend for having a "stick it to the man" attitude, but bailing on the team for elevator music is so trash. So, Am I the Asshole for being frustrated with my work friend? Also, they wore the band shirt to work the next day. I love them for that, fr.