I am not a lawyer, so: even if a patent expires, that doesn't make patent violation commit in the past "not a crime anymore" does it? It's still subject to the

I am not a lawyer, so: even if a patent expires, that doesn't make patent violation commit in the past "not a crime anymore" does it? It's still subject to the statute of limitations? And if they knew their patents were being violated but didn't sue, isn't there also the "sue's it or loose it" clause that can be invoked to get the case thrown out?