Oh, so now it is all abundantly clear - so if I smeared some vegemite on some compression bandage and observed my ulcer healing well, we would apparently have evidence that vegemite might heal ulcers, but aha, we don't know whether the healing was attributable to the compression bandage or the vegemite.
So, we then go to shareholders and say that vegemite is a derisked proven product and we want to do a randomised clinical trial costing millions to determine whether it was the vegemite or the compression bandaging that wad doing the healing.
Apparently, all the experts said that this was the only way to prove that it was vegemite doing the healing.
Just a thought, but maybe smearing some vegemite on my grandma's ulcers without compression bandaging might have been a bit cheaper.