Roman soldiers and Parthian Travelers

[Robert Vermaat]

Because the Louisiana State University research study proves that many Roman citizens (including some Roman soldiers) were angry about their loss to the Parthians and because I can easily prove that some Roman soldiers were corrupt, these Roman soldiers had a propensity to accost weary Parthian travelers.  

So you have angry Romans and corrupt soldiers. But you still don't have any proof of Roman soldiers actually attacking any travellers of any nation due to a defeat in battle.

Lack of documentary evidence, of whatever nature, cannot be taken as a given because you can think of how those documents got lost etc.