It does seem a bit arbitrary that Toomey somehow manages to distract the Langoliers from the other passengers and the plane, which is how Dinah intended for it to go down. However, consider both Toomey's character and the Langoliers and their purpose. They cleaned up the past by eating it, and Toomey's character clearly isn't living in the present as he is utterly haunted by his past and is effectively living it repeatedly. In fact, you could say he is consumed by it, which would put him on the radar for Langolier consumption.
