The admins won't compensate for drug money. Bit silly to park 3 meters away , see all the commotion and then decide you should sell it to the drug dealer within the next 10 minutes. Also , and i am not 100% on this, i do believe that the police rule is for the same officers, not the police force in general.
Edit- Direct from the handbook (someone tell me if i'm not allowed to post this here)
3. Am I allowed to camp drug related areas in order to catch people carrying drugs, such as: The drug fields, Processing plants or the NPC drug dealers?
Yes you are, but only for 10 minutes. After your ten minute time limit is up you have to move from the area, place a marker on the map with you name and the time you leave the area, and then continue your normal duties. If you are caught camping any of these places for longer than the 10 minute limit you may be suspect to disciplinary procedures. Aside from that it is plainly unfair from both a role-play perspective and a rebel perspective and you will often find that people who disobey this rule will be reported by rebels on the forums. Be warned it is not illegal to just be standing in a drug field they must be picking the drugs.
So from the above, it looks like you have to go there with the intention of camping, sitting and waiting for people to arrive for a total of 10 minutes, which is not what happened from what you explained, it sounds like you are saying them being there to deal with someone is them camping there waiting for people, they were probably dealing with the current situation, at which point one would assume the timer is paused. will have to check the video.