That comment is still showing normally for me and isn't flagged as "deleted" in the DB.
I've had to restart my instance and block a spammy IP. I'm still learning how the rate limits work in lemmy, and my server logs were just flooded with rate_limit_errors for the last 45 minutes or so. Finally just blocked that IP as its traffic pattern didn't match any other Lemmy servers/clients. That said, my server may have missed some announcement messages or something. I dunno.
On another note, I did leave a comment somewhere the other day and deleted it because I realized I sounded stupid. Someone replied to it a day later. I also deleted, restored, and re-deleted a test comment in this thread that someone else said was still visible, so I'm guessing that one of a few things could be the case:
Sometimes comment/post deletions don't federate out/in
There could be something up with my instance
There's some other factor at play.
There's a bug somewhere
I've got to get to bed, so that's as far as I dive into this tonight.