If I was Carla I would be tempted to do one of two things.
1. Stuff Roys head down the bog and flush it.
2. Totally deny all involvement, officer Roy had access to my factory to delete the CCTV and dump the clothing and he hates the Barlows as Tracy claimed Amy was his his and blackmailed him and Hailey.
Smug Barlow and his loving that women are fighting over him is sickening, he dosent care about Simon just having the power.