But in reality, just about any curve of roughly exponential increase form can have a couple of straight lines imposed on it such as to passably plausibly account for the entire data set. Especially if you set the time axis long enough so the increase will look like an abrupt event rather than a gradual one. Nice correlations can be found for each line with its corresponding part of the data, and impressively high significance levels pointed out. But it does not follow that the increase is usefully understood in terms of such pairs of lines.
McDonald and Paul featured remarkably small graphs of the increase, which tend to give the impression that there was no increase before their "changepoint". And they use a whopping 50-year timespan. It would be better to have larger (taller) graphs around the critical period so we can examine the end of the "level" section more closely.
I hold a uniquely "privileged" position of lack of bias in relation to this dispute. I have no personal connection whatsoever with autism, with no family or friends affected by autism. As a thus consistently independently-based researcher there is no pressure on me to go along with any particular institutional position. My only connection with autism is that many years ago I discovered and later published the uniquely unchallenged, comprehensive, theory of autism, long before there was any talk of an increase let alone the slightest linking of it with vaccines or even mercury. Furthermore, autism is just one of my numerous great theories, so I am not here gripped by all-eggs-in-one-basket ego syndrome either.
From this background, I and the antiinnatia theory really don't give a hoot as to whether or not any vaccine causes autism. We will just follow the facts wherever they lead us.