Pretty unprofessional behavior by the LEOs there. Stupid if they knew that they were being videotaped.
So what was the alternative? Let her go loose after she was seen going over the limit in adverse conditions? Troopers have a good feel from experience how fast she was going, and she acknowledged that by saying she was late for work.
No good deed goes unpunished; she had a 50-50 chance of getting off with a warning.