Assuming, as we must, that the credits are correct, then maybe the Vicious presspack is wrong - I haven't seen it, so I don't know. It could be wrong if Mark Ravenhill was indeed announced as co-writer at an earlier project stage, as Xanderl half-recalls. Or maybe the Times weekend reviewer is just sloppy. Out of interest, who is it? I don't subscribe, so Times is a mystery to me.
Epi, is your persistence on this topic intended to imply that Mark Ravenhill did indeed co-write it but then insisted on being uncredited? Do you have evidence? Or is it just a hypothesis? Or are you just being mischievous (as usual)?