system
Given the following post, respond as if you're commenting on Reddit:
human
[Avengers: Infinity War] Why didn't Proxima just shoot Cap?

Her spear could fire energy blasts.  Why disarm herself in the presence of multiple enhanced individuals in the train station when all she wanted was the Soul Stone?
gpt
Went back and watched the scene to check.

1) First, Proxima seems to be able to call back her spear after it's thrown, as that's what she does after she gets beamed up.

2) Her blasts seemed more for disabling and stunning rather than outright killing. At least twice Scarlet Witch, an otherwise physically un-enhanced human being, was able to take direct, blind-side hits from it and get back up.

Perhaps she imagined this was just some random, ordinary human interloper, and just wanted to get rid of him quickly, and so she threw the spear to kill him instead.