I guess we can stop our conversation there.

Yes it has travelled via airplane. But the spread in certain areas has been much quicker than others. Airplanes go everywhere so that makes no sense.

Why is the U.K. weeks behind Italy but on the same plane?

The reason is that a few cases don't always spread at a high rate. But eventually the spread gets going and becomes widespread.

There is a reason that trajectory graphs don't start until a fixed number of deaths. That is when it gets out of control.