The mapper used different DS for 1/2 and 1/1. This can be done on Normal difficulty, but it is the easiest diff of the set so it looks ambiguous. The song is not fast at all (128 BPM) and these different DS are still readable by beginners.
But things like this 02:43:425 (1,2,1,2) - should be avoided.
The last kiai is harder than other kiais before, and that makes the difficulty not balanced throughout the map, and imo, that's not good for the easiest diff.
You can see with this long pattern 03:02:175 (1,2,3,4,5,1,2,3,4,1,2,3,4,5) - and compare to 01:54:675 (1,2,3,4,5,6,1) - . There is 2* less density.
So, i conclude, imo, there must be an Easy diff, because there are too many 1/2 rhythms which are difficult to handle for a beginner.