recoil vs fall out

recoil is a noun but fall out is not a noun.

Word	Noun	Adjective	Verb	Adverb
recoil	Yes	No	Yes	No
fall out	No	No	Yes	No

As verbs, fall out is a hypernym of recoil; that is, fall out is a word with a broader meaning than recoil:

Other hypernyms of recoil include come about, go on, hap, happen, occur, pass, pass off, take place.

recoil (noun)	fall out (noun)
a movement back from an impact
the backward jerk of a gun when it is fired

recoil (verb)	fall out (verb)
spring back, as from a forceful thrust	come to pass
draw back, as with fear or pain	have a breach in relations
spring back; spring away from an impact	drop out
come back to the originator of an action with an undesired effect	leave (a barracks) in order to take a place in a military formation, or leave a military formation
	come as a logical consequence; follow logically