That part seems to qualify as an unsolved problem. But could anyone have taken the scanned data (or the GIF file) and used it to open a bank account in your friend's name? That seems like the main issue that is genuinely solved by correct implementation of this type of system.

Already today nobody can open a bank account in my name with just a picture of my passport, as the original would be required. My passport doesn't have any of the "eID/CAs/ZKP/PKI", so the question of "what exactly the addition of it solves" remains open.

My national ID card supposedly has some of it, the 17-year olds who want to pass as 18-year olds usually show a doctored gif file of their ID card, with a year of birth one or two years before the actual one; this works in ~98% of the cases.