BEM mesh artifact

Hello MNE experts,
We have had difficulty with our current protocol creating our BEM
meshes. Specifically, our outer skin BEM surface layer contains a
strange artifact/error: large spiraling loops are created, which extend
well outside the head.

I am not sure exactly what information you need, but our data are
located in:

/space/theta_001/users/Sarah/Stern/Subjects/SBT_MEG_002/

and

/space/theta_001/users/Sarah/Stern/Subjects/SBT_MEG_003/

Do you have any idea what could be causing this artifact on that
particular surface?

Thank you for your help!
Thackery Brown