The result at Sydney Cricket Ground hammered Australia's net run rate, which will be used to separate teams tied on points in the standings, and left them almost certainly needing four Group 2 wins to make the last four.
"There was a bit of hurt in the change room after that one," Stoinis told reporters. "It's the first game of the World Cup and if we look after the rest then everything should be fine.
"It does leave us in a position where other people might be in control. But if we go through and we've only lost one game and we don't make it, I think we can probably, to a certain extent, be OK with that.
"But for now, the next focus is Sri Lanka."
Stoinis said that Tuesday's match against the Asian nation was a chance for his team to set things right.
"This is what we love to do," Stoinis said. "We know that we've performed under pressure. We know that when our backs are against the wall we can pull out the performances we want.
"We trust ourselves and we trust each other. Sometimes the environment helps create a bit of that. And it's tongue in cheek but we still feed on it and joke about it and stir each other up about it. Hopefully, we're alright."
