Should this flexible ducting not be rigid?

[PNE123]

I recently had a bathroom fan fitted with the flexible ducting going through the loft to the outside wall. From what I have read flexible ducting going through a cold space should be insulated to prevent condensation and lead to problems like legionnaires disease.
Having read further from what I can gather flexible ducting should be no longer than 300mm and clearly it is longer than this.
So should it be replaced with rigid ducting to meet building regs?

 

[motorbiking]

It looks like you might have a fan designed to go in a wall or window, trying vent a long exhaust. It really needs to be a more powerful inline fan, otherwise it simply wont clear the exhaust through the duct and you'll get water pooling in the pipe. You need something like this:

Bathroom and Shower Extractor Fans