Is this a scratch or a venomous snakebite?

Tom is a 55-year-old farmer, brought to your rural ED by his friend, Shane, following a suspected snakebite.
They explain that as Tom was helping clear rubbish from around Shane’s garden shed, he noticed a snake.
When Tom attempted to kill the reptile using a shovel, it struck at him.
Tom saw there was a scratch mark on his leg, and within minutes, began to feel dizzy and nauseated. Shane helped Tom to his ute and drove for 20 minutes to the ED.