C'mon, the Evening Standard? Anyway, he must have been rehearsed in the *role* (else the Stratford run would have been hilariously awful had Tennant's back trouble kicked in then), just not the proscenium set-up. Oh no, he wasn't quite sure which of the "walking off through the audience exits" had been changed to "go out downstage left" or "go out upstage left". I bet you any money he knows where they all are now, and it's not like you would've even noticed, seeing as you didn't stay in the end.
Exy, I don't think anyone's under the delusion that this play would've sold half as well with just anyone in the title role. But, as I believe has been said on another board, it's an important reminder to people that s*** *does* happen in live theatre, and if you can avoid it, do NOT pay ridiculously over the odds like the eBay people did just to see one particular cast member.