Unfortunately Klein, it is possible to mis-assemble the octalink, though intuitively it would appear to be a no brainer like taper square assembly.
I, ahem, have done it and there have been prior threads attestling to others
who have managed the feat. Attention needs to be paid to the length of the
splines and a calibrated eyeball used when the crank is assembled. The crank should slid on at least the length of the splines. When tightening/torquing the crank bolts, attention to the movement of the crank onto the shaft should be paid. If any wobble is left in the crank when torquing is complete, the splines are not seated, unfortunately this is sometimes only apparent under riding level torque. The result is the axle splines chewup part of the crank splines. This is
where the calibrated hand, eye and brain come into play: ie experience in the art of bicycle mechanics. Steve