I stand corrected - apparently my burst with the Inspiration buff is sufficient to keep me atop the threat chart. So it goes.
Suppose I'll tweak my rotation a bit and hit my force camo at the end of Inspiration instead of right after the first taunt, maybe that'll help.
Thanks for the education, all.
Or just have the tank taunt as they are leaving the tank, or do a tank swap.... either of those two things will prevent the dps from stealing agro during the shield phase.