I'm just wondering: Is this even possible? Does it mean you can complete a 99% hacked target after breaking disguise?
(In case the enemy team really forgot to remove the hackbox. Ha. Ha. Ha.)

Yeah, I was wondering that too. How the hell? I'm only down to six locked achievements!

You could just hack until like 99% and then disguise, then hack the rest! Easy peasy pants!

Disguise. Watch teammate get shot right in front of the gate at CCity while delivering the bioweapon. Get trophy.

No, I'm sure this isn't the only way, but it's an option.

I got this one on Resort. I hacked it to about 97% and grabbed a disguise. A friend came and finished it off, but I still got the achievement.

I have no idea how I got that one, Revo :s

Think I did it the way JF2L did it, I had other Operatives nearby who also hacked

I tried this method, only I stopped at 93%. A bot came along and finished it right after I disguised. I dropped disguise, but before I could start hacking again the bot finished the objective. I got credit for it anyway.

Easiest way to get this:

• Set up a Private 1 v. 1 match on Reactor. You play as an operative. Your friend plays as anything he/she wants.
  
• Go hack the objective. When it gets to 99%, press right trigger, which stops your hacking.
  
• Kill your friend and assume his disguise.
  
• Go back to the hack point and face it suqarely. Press right trigger to break your disguise, then hold down "x" to complete the hack.
  
• Achievement unlocked.

It's easy.

Be an Operative.
Plant a hackbox on the objective.
Get to 99% completion.
Disguise yourself.
Finish hack.

- I did this achievement on Solo campaign, I found it to be easier there.