Glitch in Hook Theory

http://www.hooktheory.com/theorytab/view/kenji-kawai/mobile-suit-gundam-00---fight

In the end of verse there is a 2nd inversion with sus 4. How is this possible?

This is not a bug.

This was available in older versions of Hookpad before sus2 was implemented, and remains to implement the inversions correctly for compatibility. Use this fork.