Signed up to report some problems with the 4th gen legality checker.
Both these Pokemon are private, if this is a problem I can post screenshots.
Scyther. This was caught during a chain (I had to start a chain because of the lack of correct encounter slots), but it says "Possible method J/K slots don't match encounter." Since starting a chain overwrites encounter slots any chainable Pokemon (any Pokemon from DPPt found in grass) has no invalid spread/slot combos.
Above Scyther now a Scizor. Same Pokemon as above, now evolved into a Scizor, this time it says "Static / Magnet Pull encounter.", the only problem is that Scizor has never been catchable and Scyther is not affected by Static/Magnet Pull.
EDIT: Another Pokemon, Shinx. This is a chained shiny with a Static lead but it shows "Unknown encounter.", it's like this for all the shiny Shinx I caught from the same chain.