Its the damned if you, damned if you don't again
If the officers did nothing, then the complainant could file a complaint with the PD and the officer could face disciplinary again against them for not doing their job. That could effect promotions down the line, days off, and lost wages.
Not only do officers face the stress of being shot at work, they also face the stress of, even if they did nothing wrong in handling a call, they could still get complained on by a citizen that didn't get the satisfaction they thought should come to them
I got written up once for refusing to write a misdemeanor citation to some kids for playing basketball at the dead end of a street. The person who complained called my supervisor at the time and said I wouldn't do my job. I argued that 10 year old kids were not hurting anything by playing because they were not obstructing the flow of traffic, which was the basis of the City Ordnance. She complained so much, I got written up. Even though it was my discretion to issue citation and under the law