I also filled a bug report about this within the game.
My shadow is on empire side. Tactical has the names for Assassin skills. Clairvoyant strike properly grants the 50% and 100% (1 and 2 stacks) crit chance increase. WB however does not.
Also the DR from Shadow's Respite (leaving stealth for 15s or using Shadow Strike - 15% DR) is bugged / not granted either. The DR from the lvl 78 passive in the talent tree, works perfectly (and it is displayed on your character details in the defense section).
Am not sure if WB should also increase your critical chance by 10% and 20% (at 1 and 2 stacks) since it does provide Clairvoyance stacks - same way as Clairvoyant Strike does, the buff shows, and stacks to 2, but your crit chance is not increased. Clairvoyant Strike properly grants the critical chance increase.
So my guess is that WB is bugged in the code somewhere, as it grants the buffs that Clairvoyant Strike does - visually, but does not apply the effects associated with those stacks, hence making the tactical Blade of the Elements not work unless you apply the stacks with Clairvoyant strike (so you can't prebuff your stacks with 2xWB before a fight to get a good opener).
I tested this on the target tummy on my ship several times and it's clear that the problem lies within Whirling Blow.