Since Bishop Valentine only joined ROCOR in 1991, then left in 1994(let's not forget that he rejoined again in 1994, after the union with the Cyprianites!), that gives a three year period for his consecrations. During this time Valentine was suspended by ROCOR until further investigation into the consecrations. The consecrations didn't end, so he was rightfully defrocked for disobeying Church orders. Three years is not a whole lot of time in the Church world.
What do you mean the "episcopal consecrations weren't comdemned until much later"? We're only dealing with a three year period of time here for consecrations to take place and ROCOR's reaction to be made, some of which Valentin spent suspended, which shows that action was taken. As has already been said, even if ROCOR had treated him a little roughly, is this a reason for schism? A crime which cannot even be cleansed through the blood of martyrdom?