Hmm.. its been a few days since this happened.. (my comment was a day later)
But I know for sure that I found a way to deal damage more than once per turn, which according to your explanation shouldn't have been possible? It happened at least once, though I only tried for a turn or two, before switching to a strategy for getting rid of mobs. So I'm not 100% on the specifics, other than that I succeeded in dealing damage twice in a turn at least once.
Taking a second look at a screenshot of my set-up, I likely didn't have another weapon, so its possible it got dispelled via Scratch? Ooor possibly an empty mug??
Just to double check, a cleaver build would also only have the first cleaver hit and all subsequent triggered cleavers would be dodged?
Can confirm its a complete nightmare with cleaver build and I reorganized to only have main / few cleavers to get triggered before this fight to not wait forever.
I'm not sure what exactly you've used to deal 2 hits in one turn, as I said weapons with vampirism miss the main hit and deal damage from vampirism but thats pretty much all that goes into my head. Although I kinda remember on some multiattacking build I've seen like 2 hits out of bunch hitting the boss. My best guess is that pure vampirism weapon (there is dagger with just 2vamp and self-poisoning halberd) may remove dodge without triggering next one? Because around that time I was rocking Shield Spirit setup with one of my weapons being that vampiric dagger:)
As for the scratch, I never really used it so not sure how this one interact with boss dodge mecnahics. Should actually try it next time I meet him:)