I've spoken with Homebound about this incident. Firstly, he only warned you, the ban was an auto ban by console that he had no control over, which has already expired.
Now as you don't have any evidence to support your version of events, I have based this off of what Homebound remembers. You witnessed a detective shooting at someone, and you then shot that person. This is a valid kos reason.
If this was actually what happened, then you should not have been punished. Therefore, I'm willing to give you the benefit of the doubt and remove the punishment, however, no action will be taken against Homebound due to the lack of certainty, but I have informed him of this situation and he knows not to punish for this in future.
Thanks for making the report. Please feel free to report again in the future when you have concerns about staff.