> the bar raiser is the key person to impress

Not quite true. The Bar Raiser's job is to ensure the hiring decision is data-driven, bias-free, and is a good hire for Amazon - not just the team (this does create some tension between hiring manager and bar raiser).

I've been on plenty of loops where the bar raiser had a bad experience with the candidate, but the rest of the loop had good data and the candidate was hired.