The flashback in which V escapes from the flaming Larkhill facility was done in-camera with CG only for touchups because of cost issues. Stuntman Chad Stahelski wore only a G-string and cooling gel to protect him from the flames while performing the stunt.
In the scene where Evey gets her hair cut, it was Natalie Portman's real hair they cut. They had only one shot to capture that scene, and everybody was quite nervous if the scene would turn out usable.
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