Truth and allegations in history

A review by Nick Lloyd of recent military history books (TLS, August 10 2018), contains the following remarkable statement.

Inevitably the much-derided peace of 1919 at the Treaty of Versailles (with its allegedly punitive treatment of Germany) hangs over the final years of the war like a black cloud.

Since when was the treatment of Germany “allegedly” punitive? I thought that was one of the reasonable certainties of history, the kind of “fact” that everyone agreed on. Of course, facts in history cannot have the same certainty as facts in science, but in both science and the humanities, there is a common agreement over many issues. When an academic (Lloyd is reader in military history at Shrivenham) questions a commonly accepted statement, the reader expects some kind of explanation for not accepting the consensual position - but none is given in the ensuing review. 

 Given that Germany was not invited to the negotiations over the treaty, and had to pay the equivalent of £284bn at present-day prices, I think it can be assumed there was an element of punishment about the treaty. The disagreement among figures at the time was whether it was too lenient.