I can think of no reason to do what the caddie did other than to gain information for the next shot and I agree with the call but have a question.
The rule says you can't touch the sand with the "intent" of using the information on the next shot. Would the DQ have been appropriate if after touching the sand the caddie never spoke or signaled to Pinto and Pinto simply hit his shot without any information from the caddie? That would imply there was no intent to use the information since there was no attempt to communicate it. Would/Should that have changed the call?