Zeph missing obvious lethal

So, by turn 8, my opponent has 14 health. I swing at him with my weapon, putting him down to 12. I proceed to leeroy into coin into zeph, giving me 2 additonal mana for a windfury lethal, yet he doesnt offer it?

How come? is it because it doesnt register the coin?

https://hsreplay.net/replay/Uk5WfAbFeCA5XrukuUQKy3

Turn 8

Edit- from talking to some people, it would appear that attacking first makes it more difficult for zeph to realize windfury can provide lethal, that’s silly.