They couldn’t use a normal charger because they didn’t have an adapter.
There really isn’t a “normal” charger since there are several different standards that have been used both in the US and worldwide. If you really want to go there and try to get pedantic about it though, the “Tesla” charger is now the North American Charging Standard. The standard that everyone is switching to, where other manufacturers are going to be providing adapters to their existing customers with old CCS plugs since new models will use the same Tesla connector and those old chargers won’t work on the new models going forward anyway.
Apparently no one told them that they needed to find a Tesla charger.
They also apparently didn’t think of looking for anything on the screen inside the vehicle itself that will literally navigate you to the closest charger either. Or look anything up on Google on their phone about it either. They just let the battery completely drain while driving around without trying to do anything to find a charger it seems.