In regards to the "timing" I think Liz mentioned it because she does realise what she's doing to an extent, whether consciously or not she seemed to be expressing how her feelings for Jason affected her actions and didn't want to make the same mistake. Liz believes she was a rebound for Jason which he confirmed when he went back to Ho twice, so Liz said it to Nik because she's in the same position again believing he'll go back to Britt eventually