Yes, O’Mara had a little bit of rehabilitating to do on cross with respect to the tape. I wouldn’t say the tape was extremely damaging.
For example, the female officer asked why GZ didn’t identify himself as being with the Neighborhood Watch. That was a reasonable question. GZ’s answer on the tape was not strong enough to compensate for not identifying himself. Thus O’Mara asked Serino about that question and answer on cross.
No, it wasn't. Turns out neighborhood watch protocol advises to NOT tell a suspicious person that you are neighborhood watch. This is advice coming from SPD, to people who are interested in neighborhood watch. It makes sense too. If the person is a thug, you just identified yourself as being worth more points.