Al Whittle. "The cops involved would have arrested him, spoke with him, asked him to go home and stop being a public nuisance or danger, atempted to reason with him - all before that incident you see."

That's pretty perspicacious isn't it? We don't even know what the man was arrested for, or what his behaviour was like before he entered the station. AAMOF it looked to me as though he'd been arrested on suspicion of handling drugs or stolen goods or something similar. (Note the blue plastic bags which the sergeant's oppo was counting before he assisted the said Sergeant in his relentless search for the truth.)

However:-

I have googled the name of David Healer several times and the only results I have been able to come up with relate to the trial of Sergeant Harvey and his oppo. Ipso facto, either:-

the case never got to court or,

the offence which Mr Healer was charged with was so trivial, even the neighbourhood press didn't consider it worth reporting.