We have seen it, not around a towel bar, but on a Formica surface. On our our Basecamp X we have had three bathroom doors replaced due to cracking from fastener holes. The problem would be easily eliminated if the factory took the time to countersink holes drilled into all Formica surfaces. By not countersinking the holes, micro cracking is left from pre-drilling the fastener holes.
After the last replacement I removed the locking mechanism and countersunk the holes myself. Our door replacements were definitely a lot easier to fix, than your wall with the hydronic heat system. Good luck with the repair.