Might be.
A well known issue with early aerobatics pilots is that "stick straight back" is very hard to do. Because the force generated by your arm is never straight back, but in the direction of your elbow (partly sideways, typically under a 30-45 degree angle), the stick doesn't go straight back in a pitch up. This leads to skewed loops and so forth.
Maybe the same thing is happening in your flare.
The other reason might be the secondary effect (both roll and yaw) from closing the throttle.
To verify that this is indeed the cause, look at the end of the runway just above the coaming, and see what the coaming is doing relative to the horizon when you close the throttle, and when you flare the aircraft. You might detect roll and/or yaw that way, so you know how to correct next time.