NO self respecting ground crew will let a plane take off caked in mud, period.
They may land that way, but before they take off I promise you they were wiped of most of the mud clumps. Not only does that make it dangerous to fly, it's like step 1 on a preflight walkaround
There's worn, there's dirty, beat up, etc, but this just looks "dark."
Some P-38s in this game share the same problem, IMO.