The diabetic girl, Tina, passes out due to a low blood sugar. She is given a shot of insulin which revives her. In real life, insulin is used only to treat a high blood sugar. If a diabetic who passed out was given insulin, they would die.
The case of RPG rounds Abraham finds in the abandoned Hummer have the stabilization fins deployed. These fins are deployed only after the round is fired.
The walker soldier Ford finds hanging from the overpass has an RPG-7 launcher strapped to his back. The RPG-7 is a Russian invention and is not in use by any branch of the US military.
When Tina enters the burned greenhouse, Daryl has either forgotten that those appearing dead may still be walkers, or simply doesn't care to remind Tina.
Abraham takes the RPG and cigars, yet leaves an armored military vehicle (that is apparently in perfect condition) behind.