I did see that comment but as I read that it seems to only refer to that particular singular (and seemingly first) request for access. Even in that comment they say can't even definitively rule out that it wasn't an attempt at emergency access, just that it was extremely unlikely because of SOPs. That in turn might perhaps lead to the conclusion that the investigators had no way from the audio data of ever telling which "code" was used for entry.
Maybe it's more clear in the original French langage version.
(Edit to add:spent too long typing - I appreciate you maybe can't answer but is the buzzer sound for normal access the same as the buzzer for emergency access?)
As for the comments about the " Alt knob"
on the MCP
Thanks for your comments, I wonder if the "one second" is plus or minus. I'm not planning to try it but you could certainly wind most Boeing MCP alt selectors down to 100' in not much more than a second.