> Unless they did something truly bizarre there wasn't room for being subjective

Without having been there, I have a sense of what you mean, but I do want to add:

1. Statistically speaking, there will misinterpretation and even outright errors on the part of interviewers.

2. As feedback gets passed up the chain, most processes I know about are not formulaic. People make judgment calls. They might be more or less consistent w.r.t. following some ideal, sure. A company might pride itself on consistency and that might be good. Another company might pride itself on adaptability -- changing a process to suit the current need, because maybe the old process wasn't that great.

3. There _will_ be differential treatment, as perceived by the interviewer, even if you behave _identically_!. Cultures are different, comfort levels are different, styles are different! Saying the same thing, with the same tone of voice, with the same timing might have different effects on different people.