1. Take the files and figure out what to do with them so they can be read. This isn't a hard problem.
2. Ask everyone affected to email you the photo or a new photo of the documents. We'll just take it on trust that you do so honestly because there's no way you would've seen this coming.
That's not what happened at all. The college board admitted their fault and are letting students take the test again. Even without that, they mentioned in their FAQ that JPEGs and PNGs are the only file types acceptable and even sent out a tweet (which should have been an email) a week before especially for iPhone users to let them know how to take pictures as JPEGs.
I agree with the people blaming the board for not having a standard image input field that lets the OS know when to convert images to JPEG but that is their only fault and I wouldn't have thought of that as a bug deal if not for this issue. While I'm all for open source media formats replacing what we have, HEIC certainly isn't big enough to be considered as among standard input options. Also, isn't Apple themselves infamous for not supporting certain formats throughout their devices?
That's like telling people what brand of pencil they are allowed to use to mark paper. It's not germane to the test and improperly shifts the burden to the student when the technology to automatically screen already exists.
Can you say the same about a photo and identifying the file format?