Not sure what you’re asking when you say “on what grounds”.
The warrant was issued without any evidence supporting it, which I thought I made clear in my comment.
I did read it, it’s linked within the article OP posted that we’re replying too, or maybe it’s a couple clicks away.
The fact that shit hit the fan seems like a red flag to me that things were wrong from the get go. Cops get away with misconduct every day, for it to make national news means they probably acted indefensibly inappropriately.