If you think of a 1-D plot of these two quantities over time, you will get two cones widening to the right that eventually intersect. The point of intersection is the earliest time that a merge or split could happen. So everything comes down to bounding crossover and triangle priorities over time. For the triangle priority, just consider all the possible camera motions that could possibly happen over time. If your camera can jump around arbitrarily, then no bound is possible.
Typical motion is constrained, however, to some finite maximum speed of the camera position.
Think for example of fixing your reference frame to be that of the camera, and think of the motion as occurring entirely by the wedgie. Then the wedgie will move by at most the maximum velocity per second, so and point in the wedgie will lie in a sphere whose radius grows linearly over time. A slight modification you might consider to the reasoning above is to allow very high rates of change to camera orientation, but still have a finite bound on the velocity of the camera position. Now the errors are rotationally invariant. The reasoning above continues to work if you now always imagine your camera as pointing straight towards the wedgie.