The smallest trees we have around here are about 40 feet tall with 1-1.5 foot trunks.

Are you seriously insisting that you can’t believe that “small” tree doesn’t refer to a 40+ ft tall tree? Like to what end are you making this ridiculous point?

Double-negative confusion? Is the word 'like' required?

Like maybe they aren't seriously insisting they can believe that "small" tree does refer to a 40+ft tree.

Surely there are trees smaller than that, unless they just pop out of the ground 40 feet tall?

I assume a small tree means a mature small tree, not a sapling.