One does wonder
>>significant walking difficulties, enough to impede the man's escape at the first dramatic signs which preceded the eruption<<
What would the Romans consider a 'dramatic' sign? Big V may have been smoking & giving the odd wobble for years before going bang (several hundred MTs worth) and as most living people know, lava flows aren't that quick or widespread.
Knowledge of the physics of big pyroclastic eruptions is a recent thing - previously most witnesses were either toast or not believed.
Biting the hand that feeds IT
