‘Never accurate’ is way too strong in my opinion.

Lots of evidence in courts is based on witness testimony. Witness reports can be unreliable (especially when filtered through cops and lawyers) but It absolutely tracks that cops would arrest someone after a deadly shooting for yelling something like that. The older dude they arrested and released, they ended up later arresting for obstruction of justice, which seems like something cops would charge someone with for wasting their time.

Unless you have something that contradicts the witness, there is no reason to doubt it.