When Leela and Fry walk across the ocean, the water remains solid beneath their feet, but when they make their toast, the champagne moves as they gesture with it.
When Leela is catching the remote and pressing it once every time it has recharged, Fry manages to continue his sentences one after another. This is despite the fact that Leela is sending him back 10 seconds at a time and he should not remember the last 10 seconds he said.
When Fry gets stuck in the loop while jumping off the top of the Vampire State Building, he delays for about a second before pushing the ten-second rewind button after it recharges. He reappears less than one second after going off the ledge, so if he tried pushing it sooner and sooner each time, he could make it back on to the ledge.