How do we repair this oops that hubby just made?

There is particle board or maybe plywood behind it.

We put eternabond on all the areas where ladder was
screwed to back of rv to ensure no leaks.

Hubby still wants use of ladder after he fixes it so he
is figuring how to make it more structurally sound...
looking for 1/4" diamond plate (beefy) thick.

For now the duct tape will work...rain is coming this
weekend...yeah should have been camo duct tape so
no one would see it.