Round table

Please explain, I'm confused.

Logically, you can't retreat in this case.
You used magic, and the fact that it didn't deal damage due to the opponent's reflection is their special ability. And it fits perfectly into the concept of "any damage".
Formally, you can nitpick... although the phrase "used combat magic..., which in one way or another dealt any damage to the opponent" means you used combat magic, and it DID deal damage in SOME way (in this case, equal to "0").

Added 2 minutes later
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