I think that what they did was basically the same thing! They BOTH slept with other men.
Sam is single, but slept with a married man, however SHE is NOT resposible for Ric's choice's.
Liz, a married woman, slept with another man. It doesn't matter that her husband cheated first, it still does not make HER cheating OK!
Plus SAM DID NOT GO LOOKING FOR RIC THAT NIGHT! WHILE LIZ D-E-L-I-B-E-R-A-T-E-L-Y SOUGHT OUT JASON (not ran into him accidentally) that night.
They BOTH made the same mistake, but of the two SAM has owned up to her mistake much, much more than Liz has.
To me Sam HAS owned up to what happend, to Jason, Sonny & Alexis (in that order). While Liz is still acting as if she's not sure how her ONS happened - She needs to admit that SHE made a choice and face the consequences - like Sam has!!!