If you look at the Wikipedia Article on the ST1300 under the Pan Weave section they talk about this. There was an officer killed possibly due to the Pan Weave. Then they mentioned how a test was done to try and determine if there was an issue. This rider also experienced stability issues and went down and broke several bones. I think this is the test that they did to look into the issue and after this test they removed all ST1300Ps from service as Police bikes. As I mentioned they still use it for medical first responders. So if Avon was trying to distance themselves from this, as I mentioned we will never know.
Here is a BBC News Article on the issue as well Motorcycle News Article. They both hint that the heavy loads that the police carry in the form of communications and emergency equipment may shift the center of gravity back enough to cause the issue. Well we are known to run 2UP with loaded top box and saddle bags. The difference is that we don't need to run at triple digit speeds while doing it.
one thing to point here is that our emergancy st1300 bikes were more than just cosmetic changes from the original bike, due to the loads expected to carry they had uprated suspension aslwell as being lifyed higher and the twin seat was removed and replaced with a single seat and rear pod arrangement, whe tested in a wind tunnel they showed signs of not being that well balanced at speed with these changes so it was decided that the high speed weave may have been caused by streamlining issues due to the changes made, although there has never reall bean and hard evidence to prove the fatalities but we do have to remember if an officer dies riding then the police force here will certainly look to blame anyone apart from the rider because if they gave a verdict of rider fault then taxpayers would have to pick up the tab for paying out large sims of money to the deceased family , i hate to be blunt in this way but this is what our goverment is like, take blamr for nothing that might cost the taxpayer. if on the other hand i went down the road on an ex police st1300 and i went into a weave and died, do you think that the police investigation would call honda as the culptiy for my death??? i think not, its my reckoning that they would close the case as death by misadventure and refere to my insurance company