It's the same tree in all three pictures so it's definitely a trident.
I'm fairly sure it is not. I just picked a leaf from my own trident (acer buergerianum) and it looks very different.
You can count the lobes, but it's probably easier to count the veins. I see 5, not 3.
With oer a hundred species, almost as many subspecies and then a lot of cultivars, it's not easy to identify it, but it looks more like a red maple then a trident maple. Red maples do have 3 to 5 lobes. The fall color could help identify it.
Apart from that, I would not have trunk-chopped it in such an early stage.