No, I'm sure that Cascade did make your money box, what I mean is that Cascade might also have made some of the Holmegaard-designed ones too, under license from Holmegaard.
The Holmegaard money boxes pop up far more often in the UK than they do in Denmark, and in a much wider array of colours - much like Otto Brauer's Gulvvase, some of which were also definitely made by Cascade Glass.
The similarities in quality and production method of the two money boxes, along with this verified history of licensed production from Holmegaard, does point towards Cascade as being the most likely factory for any outsourced work on this design.