If i read the code right, this can happen:
Death Strike is on cd, but we have free blood boil, we have the correct runes, it's 1 sec since last cast, it will try to cast death strike, but fail since it's on cd, and add 1 second till next cast.
So you miss a GCD. And in the rare case that it would come off CD at that exact time, it wouldnt be able to cast death strike, since it will be the last cast that it made in code.
Correct me if im wrong.
Death Strike is on cd, but we have free blood boil, we have the correct runes, it's 1 sec since last cast, it will try to cast death strike, but fail since it's on cd, and add 1 second till next cast.
So you miss a GCD. And in the rare case that it would come off CD at that exact time, it wouldnt be able to cast death strike, since it will be the last cast that it made in code.
Correct me if im wrong.