Octalink bottom brackets and cranks will indeed let you install the crank arms out of line. You have to watch for two possible errors:
1. You installed one arm one notch out of line. Cure: remove and reinstall exactly at 180º apart
2. You didn't get the splines on the crank arm and bottom bracket spindle aligned properly and the splines didn't "nest" fully. Cure: remove and be sure the splines interlock correctly.