@aral I mean, they're not supposed to use anything but a camera for a video that is meant for proving their authenticity.
This was more than a year ago: https://arstechnica.com/information-technology/2024/02/deepfake-scammer-walks-off-with-25-million-in-first-of-its-kind-ai-heist/
AI is evolving rapidly, it's only becoming easier to pull off such scams. This is why I cannot recommend video calls as proof.
I do have ideas for validation that could be implemented before you accept Gazan profiles, but none of them would be 100% scam-proof either. Some strengthening wouldn't harm, nonetheless.