Meta Software Engineer interview questions

Technical Phone Interview: A programming problem online while on the phone with an engineer. I had a HUGE unfair disadvantage because the engineer was very uncertain about the problem I was given. About halfway through, I had completed what I thought was the problem only for him to tell me I misunderstood the problem. After redoing it to meet his guidelines with the remaining time, he then informed me that "due to a communication error, my original solution was the right way". But after about 5 minutes of trying to revert the code, he said he was sorry that we're out of time and maybe next time I'd have better luck. Utterly ridiculous - I wanted to complain to the recruiter but I didn't because it makes it seem like I'm just bitter about "not passing" the interview and will be reapplying next winter.