Bernard: Oh, bugger persuasive! I've proved Byron was here and as far as I'm concerned he wrote those lines as sure as he shot that hare. (2.7)
Here's another joke thrown in for the century-hopping audience but lost on the characters themselves. Lord Augustus's complaint that Byron took undue credit for his hare (2.7) suggests that even the supposedly factual record of the game books is not to be trusted as an accurate account of what really happened – making Bernard's use of it here as a benchmark for certain truth unintentionally funny.