猿も木から落ちる (さるもきからおちる): even monkeys fall from trees; anyone can make a mistake; pride comes before a fall

even monkeys fall from trees; anyone can make a mistake; pride comes before a fall

Said kindly when an expert slips up. The point is that skill makes nobody immune, so it softens the embarrassment rather than mocking it.

A Japanese proverb (ことわざ)