Idle thought spun off from the prior discussion: If a bug reporter doesn't just report the bug, but debugs it and tells you exactly what went wrong and why the code is broken, then you should credit them with Co-developed-by, not Reported-by.

Debugging is just as much a part of development as actually writing the code is, and deserves equal credit. A strict reading of the kernel contribution guidelines doesn't imply this would be incorrect usage either. The only catch is the docs say C-d-b needs to be followed by a signoff, which would be unnecessary in this case (as that is about *copyright ownership/licensing* which only applies to writing the actual code), but an extra signoff never hurt anybody so shrug.