I did my extension at the Bangkok office recently and while they didn't ask me for my TM30, I saw they asked someone else for it so it's not true that the BKK office doesn't ask for it. It just depends.
He should ask the hotel to help him get to a hospital. Then at hospital get them to help him with immigration stuff. It's better if he sees them first before they catch him on overstay. Go to a government hospital for lower costs.
The last time I filed it in person and I'd lost the paper. The IO didn't say anything. Just told me to make sure I didn't lose it again the next time. It's now stapled in my passport.