Would you actually be able to say it if they were?
And even then:
1. Every Freemason knows what's on the Internet. Identifications have evolved.
2. The leaks lack... important contexts... about what they are.
https://www.latimes.com/local/crime/la-me-fraternal-police-2...
Source: my grampa was a mason, but didn't do any brickwork, and told me nothing.
Maybe you need num_guards-1 questions?
I doubt you could solve for 50 guards with 1 question.
If all the guards say the same thing, you're talking to the lying guard. Otherwise the liar is simply the one that answers differently.
Would that work? I think so.