I don't think civil forfeiture is what people concerned to record police encounters have in mind. That is, I don't expect that video evidence is likely to decid

I don't think civil forfeiture is what people concerned to record police encounters have in mind. That is, I don't expect that video evidence is likely to decide such cases. What, exactly, would you be looking for? In the example you mention, where a sum of cash is seized on the presumption that it's drug money or whatever, the point of dispute (i.e. whether this is a reasonable presumption) will not be settled by video.