Would be shocked if Sanchez's entourage aren't in constant contact with Arsenal right now voicing their displeasure. There's still just over two hours left in the window so I wouldn't be surprised if the briefing was done by Arsenal to tell their supporters they tried to sign a replacement and realized last minute they couldn't afford to let Sanchez leave for free after the season. I'm not optimistic, but I don't think this is 100% over.