Hi,
The larger issue is that you killed two police officers, and then disconnected from the server 3 minutes later. In some circumstances, this would be grounds for a PK, so you are lucky if anything.
Initiating a shootout or violent confrontation with Police can lead to a PK. Killing or attacking an Officer after initiating a violent confrontation leaves you PK active from officers for about 15 minutes.
In terms of the RDM angle:
You may attack Officers if they attempt to Arrest/Detain you or a member of your group, knowing that an arrest or detainment would lead to a FELONY charge (Having illegal guns/drugs/etc.) You are PK active after shooting/killing an officer.
If the player who's F3 you had was already gone, then there is no arrest or detainment in progress, and killing the cops would be considered RDM. In this case, it would be possible to look past that, as you had taken a risk by killing two police officers and there was also prior context, but you then disconnected to avoid any potential consequences of what you had done, which tells me you did not fully intend to accept the risks.
You have prior notes for RDM, RDM on cops, and LTARP - with all of this in mind I, and the other staff whom I discussed this with, believe the ban is fair. I believe you have about 12 hours remaining on your ban, so you can make it up to Kosher and Lee soon enough.