If you read it you would read " Note that the vehicle is not full custom made, most of the car model parts are taken from another car model and assigned to match this car." Meaning yes he made the car.
If he grabbed a GTA 5 Mods model and made a livery for it he could not get sued because all he did was use the template provided / pre existing skin to then make anoter. Big brain move
Thanks but also, the main big brain move is that the calipers are changed into a custom ones made by me, and car textures are in 4K which technicaly means that the car resolution is fully different from the GTA5 mods vehicle that he is talking about.