When you double click on shift, your character is limited to only walk, which is pretty conveniant when you are shoeless in a building and don't want to bleed (no bleed from walking).
However, when you aim with a gun, that state is reset and you go into jogging mod again. This is good also because when you get suprise pvp you are not stuck walking, but you will bleed out of it in a regular situation because you don't know which state you are on (unless you move forward and see if you jog or walk, but you are risking a bleed).
My recommandation would be to add an icon or a visual thing to know when you are in the walking only mod.
Would be perfect if it is also possible to fix the "aiming" to be considered the same as walking, because right now if you aim and move shoeless, you will get a bleed.