Around 33:30, Daniel is turning the steering wheel of the Jeep, but the front wheels don't react accordingly - a clear indication that it was actually being towed for filming.
At around 16 mins, Teal'c holds the phone such that the flap of his hat is between the receiver and his ear, meaning that he wouldn't be able to hear the caller.
Major Carter fires her pistol multiple times at activated rings knowing it impossible for lead bullets to penetrate.