I've never done a repair like your talking about but I do inspect and touch up silicone on the edges of where the metal frame of the hatch door meets the hatch face during inspections. Sounds like they failed to silicone the edges of the lock when they installed it in the hatch. You have me curious about mine now so thank you for the post. I'll be checking.
I think the interior of the door panel may be plywood or pressboard sandwiches between the outside finishes and glued on both sides. I'll be interested what you discover.