The second bit that is a startling difference between the two films is the insinuation of Arthur/Gay that Charles is not the real Charles but a masquerader while Hitchcock never seemed to dispute that it was the real Charles.

In fact, the opening sequence of Arthur's version is the strongest element of the TV film. But Karen Arthur needs to be complimented on choosing a fascinating alternative. In Hitchcock's version the dance is shown fleetingly (twice), but the emphasis is on the lead character Charles avoiding the cops in a small hotel. The first attempt at improvement that TV director Karen Arthur and teleplay writer John Gay introduced as a magical addition was the masked ballroom dance that opens the TV film with its handsome lead player Mark Harmon enchanting the elderly widow.

While I will be the first to accept that this remake does not have the craftsmanship of the earlier Hitchcock version, there are a few salient facets of the film that Hitchcock might consider to be an improvement over his version.

Shadow of a doubt, imdb