You misunderstand what this is. You suggested in another comment that I test the theory by trying the DFU process, but that is not reductio ad absurdum.
Theory: "the DFU port seems to be the USB-C port on the right side of the Mac [p], not on the left side."
Reductio ad absurdum: "[p] port R is DFU => [q] we should be able to execute DFU process on port R (and not port L)" We execute DFU on port R and it fails [NOT q], therefore [NOT p], so the theory cannot be correct. QED
> You haven't done so.
Theory: "the DFU port seems to be the USB-C port on the right side of the Mac [p], not on the left side."
Reductio ad absurdum: "[p] port R is DFU => [q] we should be able to execute DFU process on port R (and not port L)" We execute DFU on port R and it fails [NOT q], therefore [NOT p], so the theory cannot be correct. QED