Just put the cone back up, make it one lane wide at the flagstand. If you hit the cone or go under it, penalty. This would also keep the cars nose to tail. If the guy it front of you screws up, you can still make the decision to slow down , or take the penalty. Also nobody could b#tch about a "judgement call"

Drivers being drivers, they'll complain about it, it will lessen their chance of sneaking one in on a occasion.