[Freesurfer] hole in pial surface

Dear Freesurfer gurus:

I have come across two brains which appear to have small holes in the pial surface when viewed in tkmedit. Each hole appeared for only one slice. Performing mris_euler_number on all the appropriate surfaces yielded no aberrant results (ie, =2, no defects). Further, there didn't appear to be anything wrong with the surfaces when viewing the same spots in tksurfer. Curiously, both holes were in the right temporal lobe. I have attached screen captures of both holes. Is this simply a visualization problem that I should ignore? Or is there some other check we need to perform? Thanks in advance for any help that anybody is able to give.

--Matt Colvin