No way a 570whp M3 DCT should lose to a 520whp Camaro manual, the M3 is a bit lighter, has a lot better transmission and has 50whp more!!
Only thing I can see is if the M3 was missing some boost due to really low air density, pulley driven supercharged cars get much more affected by DA then N/A or turbo cars!
No matter what, impressive performance from the Camaro!