Shared flames removes a Priest of Berath's corrode lash on their summoned weapon

[ArnoldRimmer]

My priest of berath normally does corrode damage with his summoned great sword but if a paladin uses FoD with Shared Flames his great sword does burn damage instead. Why not both?

[Boeroer]

Obviously an oversight. I reckon this will happen with every weapon that already has a lash (Firebrand for example)?