Garen in ARURF

Ok so at later ranks on his e if you cancel his e so that the cd is reduced you can use it immediately again because of the low cool downs. Now when this happens the next time he e's he deal astronomical amounts of damage. He just absolutely shreds people. At level 1 I died in about 3 seconds to him like that. I don't know if it is the armor shreds that are stacking but it is not ok. Please look into it as it may be a bug