Why didnt Alonzo kill Jake after knocking him out???

Why would he get his hands dirty killing Jake, thats the whole point of why he tried to get the Mexican thugs to do it.

If Ari Gold saw Chappie he would say:
"Chappie makes Elysium look like Citizen ƒvcking Kane"

If Alonzo could have killed Jake, then he would have killed Jake much earlier; he wouldn't have solicited the aid of Smiley and others.

He should have killed him because Jake had a trail of evidence of Alonso's plan from the beginning. At least if he did then it would have been in self defense with no one to testify (he paid Smiley off too) against him except Wisemen.

Alonzo still owed a million dollars to angry Russian mobsters by midnight or else it was his own life. That's why you see him check his watch and head straight for his car after he finished beating Jake up.

Also keep in mind that Alonzo never expected that he would be getting his hands dirty with fighting Jake since Jake's death was supposed to be a done deal by the time Alonzo got to his mistress' house.

It would have made more sense for him to tie him up or something after beating his ass and figure out what to do with him after paying the Russians.

I think he thought he seriously maimed or killed Jake. It was dark and he threw him over the balcony, not realizing there was a roof just a few feet under it. That's my assumption anyway.