I'm sure that loosing half your payload of fuel out of only one side of the aircraft would have contributed further regardless of the thrust issue. The imbalance would have had to be corrected with the elevons as tons of fuel poured out with increased drag screwing things up further. There comes a point I'm sure that you can't do any more no matter how much thrust you've got.
I think it should be applauded that the pilot and Concorde stayed up as long as they did rather than some sceptic bleating on and waving a slide-rule about. <img src="mad.gif" border="0">