Sounds like your guy is a bit inept, if he can't know whether it's the rack or a bad tie rod end causing the slop. No, you didn't screw anything up, the guy doing the alignment apparently didn't want to mess with it more. To straighten the steering wheel, you can either crank in or out the tie rod end on one side, while going the opposite direction with the other side. This can be done on either the inner or outer tie rod ends, but it will negatively affect your toe-in if not done right. Inept part 2, your guy was to straighten out the steering wheel first, then do the alignment.