It's my understanding that a DMCA take down notice has to be signed "under penalty of perjury" in order be valid.
No, you have to sign "under penalty of perjury" that you represent the company whose rights are being infringed, and that you have a "good faith" belief that the work is infringing.
The work (CoreAVC for Linux), did in fact have a reverse-engineered system for emulating (breaking) the copy protection in CoreAVC. The DMCA takedown itself wasn't bogus, nor was any perjury involved.
It's use was inappropriate, however, as the software was designed to benefit our customers, rather than principally as a "circumvention device" (keygen, crack, etc.). Our policy is to go after people distributing illegal copies of our software, not customers finding new ways to use it.