Using ClearImporterOverride to revert an asset that is using a ModelImporter creates memory leaks and logs errors in the console

1. What happened
I've created a script that changes the importer override of a mesh to another importer and then revert back to material.

2. How we can reproduce it using the example you attached
Run the Tools/BugRepportDraw menu.

Expected: the cube is re-imported as a Mesh and no errors are thrown.
Actual: The console is showing errors about missing material and a memory leak. The console is then showing the memory leak message after every input until Unity is closed.