Maybe they could have just done an image search of what an actual marijuana plant looks like?
Our house was once raided by the King County Swat team. It too was a mistake. We never got a reasonable sounding explanation. It is disconcerting to have a team of armed marauders running round your house making a mess while their idiot buddies hold you at gun point and threaten to shoot your 3 Weinerdogs. We did not sue them because there was no lasting damage.
I'll get that is intimidating.
You should have sued them, not for yourself but to teach them a lesson. Rouge or mistaken police actions need to be punished. One false move or a trigger-happy cop during one of these raids and people die or get seriously injured. They need to be held accountable.