"If there is a large number of responders in the 3rd week it...

"If there is a large number of responders in the 3rd week it could account for large average numbers across all groups."

...but how do we know there are large average numbers across all groups? It's a blind study, so we have no way of knowing what the averages over all groups - there may be very low averages across the VF001s and very high over the placebos, but one might more reasonably conclude the reverse is more likely.

"But the question I am asking is “how plausible is it for the ulcer of placebo subjects to heal 50% after four weeks of placebo, given that they have already had at least a total of 6 weeks compression bandaging and exclude subjects whose ulcers healed more than 30% in the pre-trial screening?”

I would have thought - not very plausible is the answer.