Thank you all for responding.
The situation was an event station and the patient was an alert oriented walk-in complaining of dizziness as the result of a fall days earlier. If I had gone beyond what was specifically in the protocol to test, the extra time might have convinced the person that it was worth going to the hospital to get checked instead of waiting until the morning or not going to the doctor (I really felt getting checked out by a doctor should really happen soon). The extra information might also have helped define the problem better, I thought.
It sounds like what everyone is saying is that I should pay utmost attention to not wasting time getting the person to treatment, but that beyond that, if I don't give advice I'm unqualified to give, I can collect whatever non-invasive assessment information I feel I need, given the situation.