That is approximately 8 million times better than my printer would ever do. Very nice. If he wouldn't mind sharing his printer build that would be awesome.
Hey, that's my Thermal Detonator model (https://www.thingiverse.com/thing:2065383) Feel free to post a "make" when you painted it
2 microns would me pretty much impossible for an FDM printer, I'm guessing he printed the helmet at 200 microns, which is 0,2mm. That's a regular layer hight for FDM printers.
The helmet looks really good, I'm guessing he used this model?: https://www.thingiverse.com/thing:1947031