I think all commercial pilots should be made to wear their current pilots licence on their person, like the airlines do, like an ASIC card. This is less of an issue for airline pilots.
If you get into a taxi and there's no licence there on display, you can demand to see it, otherwise note the details, take a photo and head to the Taxi Directorate or Police. It should be no different for a pilot.
Would the situation have been different if Barry Hemple was made to wear an ID badge (he wouldn't have had one)?
I know of pilots that have taken fare paying passengers without a CPL.
When an electrician comes to your house, you can request to see their licence.... it's no different really.