User blog comment:Ygrain/Seriously, Aria?!/@comment-3201701-20121228222857/@comment-24174486-20121230122313

Well, somehow I suspect that Shepard is smarter than your average Adjutant and Cerberus troops don't exactly have the ability to create a biotic barrier to trap the target and/or ensure that their mass of grenades don't blow up everything that's not their intended target.

Nyreen was terrified of Adjutants for their ability to infect other creatures. When she saw civilians at risk, she did the fastest thing she could do to prevent more from being turned into Adjutants.

Also, Shepard learned to resist biotic impacts because they were just as annoyed about getting knocked down as every single person who ever played Mass Effect 1.