How do they know that?
I spoke with a police fixed-wing pilot that did it regularly.
OK on a good day a 135 wins hands down most of the time but when you add ice, frost and snow you need to keep the skid-equipped helicopter inside and cosy where the fixed wing [regularly warmed up] can taxi-straight out of open doors. The helicopter needs to be taken out on the Helilift and then started.
Yes the statement was sailing pretty close to the wind!
I think the need for SPIFR on the fixed wings is to get them off the ground at Doncaster to fly to areas where the weather is not closed in.
Nothing has changed in police aviation that much. If you arrive on scene and cannot see them through the window because of rain, snow or fog you are going home.... especially in a fixed wing.