Art director JJB said:

“Megan had two such bracelets. The one she lost (and the one from the “Motherly Ties” sidequest) is the one that gave her +5 resistance to poison, and also nullified sleep spells. The bracelet she did not lose, which is the one you see when Adam gets reunited with her, is the one that gives her +43% Fortitude. The world of Human Revolution is full of neat goodies ain’t it!? ;P

Nah, but seriously, one of the most common continuity mistakes made in videogames (in my experience) happen when you have pre-rendered cutscenes. What happens is that the “real-time” asset management links are broken between the in-game assets and the pre-rendered assets. It can cause all sorts of problems when designs are changed or as the story evolves and transforms. What we have here is a classic case of that. The bracelet on the pre-rendered Megan model was probably never taken off, and this problem was either entirely overlooked, or it got lost in all the thousands of things we knew needed to get fixed at some point; which in the case of a pre-rendered cutscene would have meant re-rendering the entire scene or sequence. But as far as I’m concerned, we just didn’t see it happen at all. It’s a bit like all the wristwatches they forgot to take off from the extras in the movie Ben Hur. Thanks for pointing it out though ;D”