Not necessarily. False hitch often "looks" true...coupler can appear to be almost all the way down on the ball, it's just not latched. A trailer can go quite a ways before it jolts off the ball, especially if you've got weight distribution and/or sway bars hooked up too.
I had this happen with a 10' utility trailer.
Drove 250 and never came off.
Didn't know it until I back the lawn mower off and the back of the trailer and trailer hit the ground.
Probably weight of mower(6oolbs) kept it on ball.
Checking things over later, I found that the closed latch left would fit the room between the ball and front part of the hitch.