I believe this topic highlights the core of individuals frustration with PSA; we do not know the exact grading and handling process. Thus, individuals are left to speculate what could have happened when a mistake occurs. I think the best overall advice is: You should contact and peruse PSA if you believe they indeed damaged an item.
Unfortunately, the PSA process is not well known to the general public. However, I am sure if enough people inquired about their exact grading process, they would provide one of those good old happy go lucky videos. In all seriousness, it would help better understand the handling of cards. At least have a reference point to better deduce possible damage.
Since we live in the social media day and age, where people can message companies directly, I don’t think it would be too farfetch’d to request a video of the grading process.
I personally can’t comment on the auditing aspect.
I do know that when I received cards damaged from transit, (both chipped cases) I sent them back in and they were re-holdered for free. I also sent back cards for another individual that were encapsulated backwards. They also correct mis-labels for free as well. These were all cut and dry, and have never had experience with a more subjective situation.