Stupid question...you are trying to get the key out while the gas cap is closed...right? The key will only come out when the cap is closed...or...if you push the spring down as if it was closed on the tank.
Joe
+1, that is the problem. There is only one way you can see the tabs and the spring, you have the cap OPEN. The key will not come out, if the cap is OPEN. Close it, and you can remove the key.
Do NOT ask how I know!

MP