Yeah what he said. This operative nerf was to hidden strike, acid blade, and jarring strike. It's stuff you don't get access to until lvl 36.
If there are differences in operative base damage I'm sure they will be reported soon. But it could have just been you fighting against higher level people with better armor (reduced damage) or that you were fighting people with shields up etc. PVP has too many variables like level, powers, toggles, stances, armor type/level,skill spec, shields, and just the roll of the dice to consistently give you meaningful data on this.
I'm not saying there wasn't an overall nerf but I will check tonight and repost if my non-hidden strike and acid blade related combos are off in PVE.