I thought about this too, and personally this would be my preferred outcome. Either Raghav killed him in self-defense or Mandaar got caught in the crossfire during some kind of gang war.
Today, Sharda reiterated that Raghav was bad in the past but he's changed and is trying to be good. That's gotta count for something, right?
There have been many EK shows where this has worked when they 'justified' the killing, but not sure if this show's audience would be ok with it.
The other thing that struck me was that perhaps Raghav knows that the man (i.e. Mandaar) had an accident, nearly died, but recovered, which would mean Pallavi is still legally married to her first husband. This could explain him being so frantic and not being able to follow rituals, or be a husband to Pallavi going forward. She will keep falling for him and he will keep distancing himself.
@bold: Are you implying that this is like, Mandar was given some money and threatened to leave the city/country immediately and never show up/contact anyone from his past again, jaise vo mafia waale movies mein hota hai?