This is not the official MBTA map, this is an unsanctioned redesign he made of it to demonstrate his idea for how to improve the official map. It is his property alone.
To the untrained eye, this probably looks indistinguishable from the actual map.
I lived in Boston for many years, took the T on a regular basis, had that map committed to memory at one point, and I still didn't realize until I looked a second time that it wasn't the official map.
They should certainly have double-checked this before copying it, but I can see why the confusion would arise.
Got it, well then it was probably unintentional. Furthermore, the actual damages in this are, I imagine, nil as long as they replace the texture in a patch.