"Richard J." gurgled happily, sounding much
like they were saying:

I wonder how many double-decker buses have passed that tree without
hitting it?

Since I suspect it is rather considerable, I think we can discount the
positioning of the tree itself - unless it moved recently.

Trees do move, in the sense that they grow, and sometimes they gradually
lean to one side. During this process the risk of a bus hitting it also
grows, so the fact that lots of buses passed it previously without
hitting it is not a reason to discount the position of the tree as a
factor.

How rapidly would it'd have to move in order to do that much damage to a
bus following a previously safe trajectory?