Ya know, I found its best never to do anything real fast when you are growing, do a little and watch what happens.
Neem oil is applied to the bottom of the fan leaves, you do not want to hit the buds with it because moisture can collect and cause mold over time. Also it is best to wash it off by spraying again after a couple days so the plant can breath again.
I cant tell you if it is going to be ok or not, I have no idea of the extent of the damage.
I can tell you when you go to harvest and you got some spider mites in the buds, Not creating a canopy of webs, I think its best to leave them alive so when you hang the buds and they start to dry the mites will leave the buds. They cant do that if they are dead.
BTW that pic sure looked to me like a hot spot created by a drop of water. and that bud if it is what it you have is actually a good thing. the bug in the pic eats spider mites.