......If so, how will this be explained

No he didn't (if they say he did it's a retcon), Gavin's sister identified her body.

Great, thanks!

That was the only implausible aspect of this already implausible stroyline 😉

I wonder if we will meet Gavin's sister. She was clearly in on the plan for her to lie about seeing their bodies.

I'm just glad that Friday gave us a little more insight into their reasons, rather than just for the insurance money!

Wasn't Ben in the car crash?

Logically, she must also have been the named beneficiary for any life insurance policies to pay out to, for her to then pass on to Gavin, i assume with some cut for her troubles.

Evidently not. How can he be in a car crash that never happened

I think the idea is that there really was a car crash and there were two fatalities, the twist being that the bodies recovered were not that of Gavin and Kathy, they were two random bodies which were later falsely identified by Gavin's sister.

I actually thought Ben was in the car at the time of the crash.

Pretty sure he was and he saw his mum die

Pretty sure Ben was originally in the crash. Seem to remember the episode he returns to the square had him in and arm cast as a result of injuries he received in the crash..