Which of the following is NOT an example of a severe fault?

The option indicating a complete loss of contact between the rider's hand and the horse's mouth is not categorized as a severe fault in the context of equestrian events. This is because maintaining contact can vary depending on the type of riding and the specific discipline. In some cases, such as Western riding or certain types of training, brief moments of loss of contact may occur without necessarily indicating a significant error in the performance.

The other options, such as refusal, loss of forward motion, and excessive shaking of the head, are indicative of more serious issues in the performance, as they demonstrate a clear lack of cooperation between horse and rider, a failure to execute required movements, or issues with the horse's frame and way of going. These faults can disrupt the flow of the competition and substantially affect the overall performance score.