This isn't a flap, this is cold hard reality. It's now way too late in the Window for this transfer to go through. If it were a case of just buying Sanchez then it would probably be doable.
However, so inept have Arsenal been in this transfer window that they have left it far too late to find a replacement. I was saying weeks ago, that it is madness for Arsenal to keep the player against his will but on balance that is probably preferable to them, than letting him go and having no one to replace him.
They will no doubt have to work hard to win Sanchez round to giving his all but an 80% Sanchez is better than no Sanchez is probably how they see it - and they willhave to pay a 70m (if you believe the silly fee being quoted) loan fee for the privilege
If Mahrez sale is on to Arsenal then it's back on imo so I would love to be proved wrong. That, to be honest, would be the best outcome for Arsenal from all this but it seems to me like they are too inept to pull it off.