Can you answer this riddle?

[Jello]

Two boys were playing on a tool shed roof when the roof collapsed with a crash. the boys fell uninjured to the floor below, but when they picked themselves up the face of one boy was covered with dirt and the others was clean. Instantly, the boy with the clean face ran off to wash his face, while the other remained behind. Why did the boy with the clean face act as he did?

 

[lemonyyyellow]

the boy with the clean face saw the boy with the dirty face an assumed his was dirty as well. the boy with dirty face saw the clean boys face and didn't realize his was dirty.

 

[maddieisaprettylittleliar]

He was a neat freak?

 

[L/Ryuzaki]

He washed away the evidence because he killed the other boy.

 

[&& ...Missy]

they were twins
he thought he was looking into a mirror

 

[Sousuke_Kaname]

there was a blood in his face XD