Continuity mistake: After busting out of the cake and killing the two Lunar Max guards, Boris' hand creature goes to free him. It first blasts spikes at the shackles on his legs and busts them, then begins climbing up to work on Boris' arm piece. In the shot where his leg shackles come off, you see the spike the creature shoots at them stuck in the metal and hanging off to the side. But in the shot where his arm piece falls to the floor, these spikes have vanished from his leg shackles. (00:03:35)
Answer: Earlier in the movie, the way K was talking about Boris was different than what J had come to expect of his partner. So J wanted to know what happened between Boris and K at Cape Canaveral that changed him. So more of what did Boris do to K rather than just the report of what K did.