HT/HS visc is what matters, not the label visc, doh. If you knew anything about oil, you'd know Redline 10w-40 has the necessary HT/HS visc, lol.That's why he recommended it!
I also happened to know for a fact, that the awesome PTG M3 Racer uses NOT the speced TSW Motorsports 10w-60, rather Syntec 5w-50.

I guess they forgot to ask some first-timers what oil they should use. Maybe you should contact them and explain how the "specs" work.