Your technique will get the toe correct, but as you see, not necessarily the straight ahead alignment. It's easy to fix, though...
You have to bring the wheels to the right, so loosen the clamps and lengthen the right rod about 1/2 turn, and shorten the Left rod the exact same 1/2 turn. This will bring the wheels to the right, so your steering wheel will move towards center, while retaining the alignment you worked on. I usually do my alignment on a straight, level stretch of driveway or street, and leave the clamps loose. To test, hold your steering wheel at center and let the car roll forward on the level road for about 50 feet to see how your correction did. Then roll it back and adjust the tie rods equally as needed to bring the wheels to center with the steering wheel. I save time by leaving the clamps loose until my test roll is perfect...and then I tighten them to lock in your adjustment before you drive. As long as you turn the tie rods equally, your alignment will remain the same.
Note: A little extra toe IN will not affect driveability. Any toe OUT will make the car drive terribly...it will dart back and forth and follow any bump or grain in the road. So the motto is, always err to the toe in direction.