The Iranians let them go. The Iranians squeezed the propaganda lemon dry. The news conference showed the Brits smiling in nice suits, bowing and chatting with their Iranian captors. They looked more like a visiting football team than British captives being returned.
The Iranians played it smartly. The Iranians won a real propaganda victory.
Things are not always as they seem. We need to wait for some answers. I find it hard to understand the hows and whys, but will listen with an open mind.