Not poor management at all.
The facts of football tranfers are exactly the same as in any business transaction. Predominately, a trade is only possible if the "buyer" and the "seller mutully come to an agreement.
During my career I've negotiated several mult-million pound deals and, believe me, these can (and do) take many months of negotiating. And, yes, they are not always successful; despite the hard work put into them.
He failed in his duty to the club, manager and supporters badly in January IMO.