They do, but it's nearly impossible to prove it. In my experience, given any particular situation where facts are challenging to employers, they just make stuff up and lie as easily as they breathe. It's disgraceful
And, goldie, that's normal, people being laid off and rehired. But if you are laid off, you are eligible for unemployment insurance here. It's a pittance, but enough to buy some food, at least. Organized labor used to be a real force for workers' rights here, but since the 1980's the ruling classes have chipped away at them. They have employed all kinds of PR to convince the very people they are hurting that they are operating in their best interests. A very effective political sleight of hand.