I had a closer look. I think the most baffling case is the one where the miner went from not turning to turning, but just at that one particular pixel when he's still relatively far away from the blocker. Ignoring that, when the miner started not very close to the blocker, he probably gets low enough by the time he's within range of the blocker's arm that he no longer gets turned, and further mining soon frees the blocker. Only when he started very close to the blocker would he not have gotten low enough when within range of blocker's arm, and can still feel the blocker, getting turned. Yet even closer (probably only at the last pixel before finally getting turned as a walker) and his first swing might reach just far enough to free the blocker, so he never got a chance to get turned.
So I guess maybe it's not too different from original Lemmings after all. The only case that still looks questionable is that first case of getting turned, which happens even though the miner started relatively far away from the blocker, and it's not obvious why it only works that way on that one specific pixel.