I did see the sequence, but as I said, her hostility triggered a red flag and prompted him to talk further with her. She was still legally detained so the Trooper had the right to ask her to put the cigarette out for his safety and to determine if the cigarette was being used to mask other smells.
Red Flag? He asked her a question she answered it and it made him angry. Apparently truth is frowned upon by this guy. He got testy and told her to put out her ciggy when she was signing the form. The encounter was over he was done. Anyone with two eyes can see he was being petty and trying to provoke a response so he could escalate.
Ah yes, the good ol' "masking other smells" canard...