With time expiring in the first half, the Raiders were trying everything to get the ball in the end zone.
Even sacrificing a full grown human being to the football gods. This play did not end in a touchdown, but it did end in Seth Roberts getting fully devoured by Jurrell Casey. The Raiders WR took the ball way upfield, then ran in the opposite direction like all good receivers do and flipped it to a teammate. After Roberts flipped it to Amari Cooper, Cooper proceeded to lose a bunch more yards and flip it to Derek Carr. Carr then just laid down because because he saw what Casey did to Roberts. No sense putting yourself through that if you don't have to.
This is what's known as a "smart business decision." Good for you, Derek.