Visible crew/equipment: When Ethan Hawke starts to chase Denzel Washington onto the roof of his wife's apartment, he climbs through the window. As Hawke is going through the window, you can clearly see a large stage light on a tripod, in the room behind him. (01:41:25)
Visible crew/equipment: When Jake is holding Alonzo at gunpoint in Sara's bedroom, the boom microphone appears for a few frames (immediately after Alonzo says, "It's not what you know. It's what you can prove"). (01:39:00)
Answer: They grew sick and tired of Alonzo's arrogance and probably decided he wasn't worth the effort. Alonzo was however killed by the Russian Mafia because Jake was told that Alonzo killed one of their couriers and had to pay them one million dollars by midnight or he would be killed himself.