What was illegal was telling a lie under oath during one of the rare instances when he went to court, and it wasn't the "crime" that they'd "finally uncovered."
Honestly, were I married to Godzillary, and knew how much damage my shenanigans were causing her political ambitions, and someone asked me that question, when she was only a few feet away...
I'd have stammered and lied my butt off too.
Imagine having to go home after that debacle. I'm sure Slick Willy had suffered enough before the Impeachment Circus even began.
Tom