For this, and many other reasons, if you cannot turn your camera on for a job interview, you should be immediately dismissed.Not to mention something that I personally know happened. Someone was interviewing for a remote dev job. Like our company, the hiring company's interview is basically paired programming for half a day. The person refused to turn their camera on. Through it all, they ended up getting hired. Within about 2 weeks of starting, some things started to not add up at all. Turns out, the person paid someone else to do the interview for them so they would land the job.
Yes some companies are filled with dicks, but if M76's colleague was a dick (there is a difference between drilling someone's knowledge, and being a dick to pressure someone) then its a great red flag that hey, you probably don't want to work with these people. Communication goes two ways unless one party has their lights out.