There is no air in the shocks you just have to much oil in the shock thats rebounding. I get it all the time just loosen the cap and bleed a little more oil out and the problem will be solved. I usually keep a tiny bit of rebound in them just so you know its full of oil and there is no air.

Edit: I have no idea what those shocks are. The purple shock towers really throw me off because I don't know of any of the higher end buggies that has purple shock towers.