Is life in prison a bit harsh? Probably, but it's early and I have a headache so it seemed appropriate. Here's the thing that college professors will never understand: nothing they say matters. Unless you're going into a job in finance or STEM, the vast majority of the things you learn in school are completely useless. It's the lessons outside the classroom that matter. And the lesson that this professor just taught his students is that being resourceful is less important than following the rules. He'd rather have his students NOT do well on an exam than use the tools that are available to them, in this case Chegg, to get a good grade. Yeah, it's technically 'cheating', but who cares? He still shouldn't take a "Me vs Them" attitude with his students. He should realize that they're on the same team. I guarantee this is an older guy too. No young professor is going to waste their time creating a fake problem. What a loser.
The good news is this stuff doesn't happen in the real world, kids. Your boss isn't going to care where you get the answer from as long as you get it. Wild, right? Thoughts and prayers to those students. You'll be in the rat race soon enough.