Not if the warrant was based on false information, like daisies being weed.
All a warrant based on false information means is they will likely not find what they were looking for. If they confiscated a daisy bed by mistake thinking it was weed they can still get the warrant amended for the illegal drugs found and that will still be admissible in court. He may still sue for the damage to the daisies, but the drugs found and seized under the amended warrant still count as evidence against him.
Just because the source information was incorrect does not mean a warrant cannot be amended, and the amended portion can still be used in lawsuits.
I also remind you that to be a warrant a judge must sign off on it, agreeing that the information, false or otherwise, justifies the warrant. It isn't just the police thinking you may have something, a third party must agree that it is justified based on the available evidence.
That being said, I am not sure how Canadian law handles it.
The DB