I suspect it wouldn't matter how much time that driver had because he wasn't looking properly and kept turning long after DHD was visible. And that's still making various assumptions about the speed. The meaningful question is whether it was a reasonable speed. I felt it was, but there's always someone on this site saying one could cycle slower or use another route and get up earlier or get home later in order to accommodate the extra time needed. And yet it's a "mistake" that motorists make often. Was it "a hidden bend"? I don't remember a reverse-angle shot other than the one from inside the turning. "About to turn" is not the same as "turning" and I would expect most experienced cyclists to have discovered that slowing for motorists "about to turn" sometimes encourages them to turn across you regardless - it could equally be that DHD's slowing/braking encouraged the Merc driver to turn, although I still think it's more likely that they didn't see him because they were looking only for motor vehicles. Anyway, we can't really discuss this until the cows come home because tough questions just get cut out and left unanswered.