I like his personality but what he did to the DB just wasn't alright.
What he did to the DB?
Astrid was badmouthing the night mother openly, that's a big no-no, especially in front of the Keeper who is sworn to protect her.
Cicero even said that he felt bad for stabbing Veezara, but Veezara got in the way.
If anything, what Astrid did to the DB wasn't right...