You are seriously overstating the strength of evidence supporting your claim. What you have is (strong) circumstantial evidence that BoJo went to Ukraine to scuttle the peace talks. To say it slipped out would mean that someone on the other side confirmed this theory was true; they did not. And there is nothing except this author's assumption to prove that Symonds put him up to it.
You are seriously overstating the strength of evidence supporting your claim. What you have is (strong) circumstantial evidence that BoJo went to Ukraine to scuttle the peace talks. To say it slipped out would mean that someone on the other side confirmed this theory was true; they did not. And there is nothing except this author's assumption to prove that Symonds put him up to it.