If you were at fault e.g. negligent, or unreasonably careless in causing the load to be rejected, the employer could seek the amount of money they lost from you. However, if you do not voluntarily pay it, they cannot simply take it from your paycheck without your consent rather, they would have to sue you in court and win, proving that you were at fault in causing them a loss and getting a court judgment against you for the money. Of course, if you do not have a written employment contract, you are an "employee at will" and they could simply fire you or suspend, demote, reduce hours, etc. if they feel that you improperly cost them money, since employees at will may be fired at any time, for any reason.