I honestly don't remember the last time I had found a SP episode better than the series it originated from, 'cause normally it's the other way around and SP episodes tend to be, alas, complete let-downs.
It could very well be that, not having liked the original dorama that much (I rated it 5 out of 10), I had set my expectations pretty low and was therefore positively surprised?
Or maybe that I was quite happy to see Morimoto Leo again (I dearly remembered him from the "Shomuni" franchise)?
Or perhaps that the writer was different than the one from the series, and this one is way better (considered how he managed to give some depths to those previously bidimensional characters)?
Whatever the reason, I must say I've really enjoyed this "Alibi Kuzushi Uketamawarimasu Tokubetsuhen"! ^__-