While playing co-op in Splinter Cell:Conviction with my friend I realized something.

When you're knocked out, a bleed out timer starts where your friend needs to come and basically shock you back to working condition. While you're bleeding out you're not out of the game yet, you can still get up and accurately pop headshots into nearby goons. So can someone answer me this?

If I have enough strength to get up, and I can still focus enough to pop MULTIPLE headshots into the nearby enemies... Why the bloody hell can't I just shock myself back to health?