Of course Moyes is to blame. Woodward said that the club didn't think Herrera was worth his release clause but then paid more than Fellaini's release clause (which was already ridiculously high).
If Woodward was willing to pay more than the release clause for Fellaini than he just can't have a problem paying a wee bit more (Moyes' favourite words) for Herrera. Why should he? And if strong rumours are to be believed Fellaini is earning 125 k (he must be on at least 100 k anyway) while Herrera was willing to accept less than we were prepared to offer him in order to help us pay his release clause. But knowing Moyes he most probably told Woodward how Fellaini is PL proven and how his chest control is out of this world. A complete farce this has been from Moyes, passing on a much much better player in favour of Fellaini!
He bid and valued Herrerra at £22m and wasn't interested in making him a club record signing at £34m, what's so hard to accept with that? I'm by no means a Moyes fan but I think that's a fair stance to take rather than pay £12m (an extra 54%) over what he believed he was worth.