> That feels more terrifying than some trained and experience arbitrator with respectable work history, to me.
Except when the arbitrator has a grudge against you (maybe personally, maybe more generically - racially, ethnically, etc., maybe he just read a hit piece in the newsletter and is prejudiced against cases like yours). You can have a chance to sway the mob, but you have no chance against the professional who is out to get you.
To understand American system one has to understand that a lot of things there are designed not to produce best outcome in optimal cases, but to reduce harm in sub-optimal cases. It is meant not to solve cases with maximum ease, but to reduce the incidence of abuse. Of course, since people with power - aka the police, prosecutors judiciary, etc. - are not very interested in reducing their own powers they are actively working to undermine this design. Thus plea bargains, testilying, qualified immunity, blue wall of silence, etc.