Something is inscrutable when it is not readily understood, not merely when it's utterly incomprehensible. So I can't give you an example of a lintian error or warning I'm not able to comprehend after enough research. But I can give you examples that aren't obvious to someone who is not a Debian expert but is capable of building software packages:
Digging up the meaning of these is possible, and I've done it, but it's rather a lot of bother compared to the process of creating an RPM.
As for examples of the arcane I hardly know where to begin. Why should I need a shlibs control file for a simple libtool shared library? Aren't there reasonable default assumptions that could be made? Why is it forbidden to set the executable bit on such libraries? That's the way they come out of the build process after all and somehow RPM based distributions survive that calamity. Why is it wrong to ship .pyc files? Why should my .py files be executable when they are meant to be used only as libraries (I feed the files to python directly when running built-in unit tests)?
I'm sure there are answers to all of these questions for those with the fortitude to dig through the Debian Policy Guide -- and do enlighten me if you happen to know them. But the notion that such exhaustive policy is necessary to make a large distribution coherent just isn't credible.