The key giveaway there is that the twigs are opposite (twigs branch out exactly opposite from one another, when one is missing just look for a scar, twigs/ branches fall off but they leave a scar) . So when you see opposite twigs/leaves then you have narrowed it down quite alot. Ash is another tree family with opposite structure but stems are thicker, buds different, and bark is very different. (you could google it but it is blocky). You'd likely never confuse a mature Ash and Maple bark.