Round table

I tried to determine the purpose and understand the spirit of this rule, but it didn't help – I didn't get any definitive results.

Cool :). If the rule exists in the current version, I agree that the presumption of innocence applies here – there is no unequivocal interpretation prohibiting fleeing, which means fleeing is allowed, because everything that is not prohibited is permitted. I have no questions about that. What I meant by "spirit and purpose" is the following:
I believe this rule was introduced with the goal of giving the opponent a chance to retaliate. The fact that when you attack, you hit, let's say, a resistant target (rather than hitting them squarely in the jaw...) – well, you were just unlucky, but you swung and hit – so be a good sport and take the hit.
Based on these considerations, as well as the consideration of clarity and universal interpretation, I believe Dubrovin's version is correct. And there will be no need to further define direct damage magic, as in Valentin's version. Again, we'll have to explain to every newcomer which spells are direct damage spells, and, most importantly, why they are... The very discussion about defining direct damage (why, for example, an opponent resurrecting 5 angels doesn't damage me at all, but an arrow with 120 damage does, just because it's supposedly direct damage?? There are many irrelevant nuances that arise...) risks burying the issue, again spreading the thought across the tree...
But this way, everything is clear and concise – you used magic, so don't run away.