It's odd. When on corsair I press LMB (Splashin' Around) no other skills can be triggered.
Example:
Tidal Salsh "back + LMB" doesn't trigger when LMB (Splashin' Around) is active.
Wave lash "shift + LMB" same. Once LMB is pressed it won't trigger.
Only way to get above two skills to trigger is to release LMB, wait for Splashin' Around animation to finish and then press key combination.
Cool that seems to be fixed as of 28th July patch! Thanks!