That's definitely why it was added in later. They changed the dialogue from the earlier precap and added this in instead. If he had never made that promise, Pallavi would have no reason to expect him to be clean. But now that he did, she has every right to feel betrayed.
Yaaa
And I am glad they have done that
As a partner : we all do trust our partners on the fact that we are with someone who will think before they act and won't do anything wrong ( I mean in big matters not everyday things )
So in that sense as well Pallavi expecting Raghav to not be involved in this wasn't wrong at all imo
( but I know - many ppl would again point fingers at pallavi with an excuse - which is why I liked that they didn't that open ended )
But when he himself has promised her - that's the solid base with she won't care whoever says what
She will trust him
Bcus her Raghav has promised her .