That was the situation I encountered as well at the Radisson. I had heard this before, so I didn't even attempt it. I called a taxi service. When the taxi pulled up for me, some of the shuttle people tried to grab it. Thankfully, the taxi service had my name as the person it was dispatched for.
The Radisson earns high marks overall though. Beautiful grounds with amazing pools, clean rooms, excellent guest service, and a great breakfast.