User blog comment:Suparockr/List of Plotholes throughout the series/@comment-5267262-20120721102720

I have a couple of metaphysics holes but I cannot think of a plot hole off the top of my head.

hole 1: penetrating the citadel using a mass relay. What happens when you throw something heavy at a wall very quickly? either you breath through the wall leaving a gaping hole in the wall and considerable damage to your heavy object, or it bounces off with potentially lots of damage to both. What happens when you throw something light at a wall but faster? the above but if it bounces off you have much higher accelerations involved. At no point should you phase though the citadel walls unless you can mega-scale the quantum tunnelling effect.

hole 2: unless you can use eezo to create negative mass (and even then the proposal is a bit iffy) there is absolutely no way that lifting something with biotics would work because the direction and magnitude of acceleration due to gravity would remain constant.

hole 3: I can see that high mass fields of air around you could help stop bullets in atmosphere (basically make air as good at stopping bullets as water is) but this would not work in a vacuum.