Yeah, I guess if they know the people and this is a "bad" area with the same repeat offenders,...just saying in most instances, and from my experience, cops won't follow up and would typically not know just faces so without a plate they could not do much in such a scenario. Dudes doing drugs in many cities are a dime a dozen...you call the po and say, "hey, there are a couple of Hispanic dudes maybe doing drugs in a car I got on video", well, that's a pretty broad descriptuon, so unless they can get there while it is happening, (and in this case maybe so since it sounds like he was watching it live, if he'd called the po) the video is not of much use to them if the perps are gone and also not well known
The above made point though of stolen plate \ car being a higher possibility could make the plate ID discussion irrelevant anyway.