The Stranger is essentially Doppelganger recycled as a tv movie. The only real difference is that after arriving on the Counter Earth, astronaut Glenn Corbett (who also appeared in Star Trek (1966-9) as the original Zefram Cochrane) finds himself on the run from a totalitarian state as opposed to on a mirror Earth. Most science-fiction films have some aspect where you are just required to switch off logical considerations and suspend your disbelief; there are others that it gets in the way of your even getting started. The Stranger is one of the latter. I was perfectly willing to extend the idea of a planet in a Counter Earth orbit but the idea that everything there would also evolve in tandem is ridiculous. Lew Ayres has a speech where he tries to rationalise this and only ends up digging a hole that is even more nonsensical. If the changes go so far back that there was no Paul Revere and no Florida, then it would be absurd to expect that history have still adhered to the modern world so closely as to have identical vehicles, clothing styles and that everyone still speaks American English. The further back you go in history for your divergence point, the wider the differences are going to be.
The other failing of The Stranger is that it seems like a series of half-ideas slung together without any clear idea of how they were going to be developed. In terms of the Counter Earth idea, nothing more is done with it beyond the initial scenes with Glenn Corbett in hospital. For the rest of the film, the script has appropriated the idea of a standard totalitarian society and simply becomes a science-fictional variant on The Fugitive (1963-7) with Glenn Corbett on the run pursued by lawman Cameron Mitchell as he tries to find a way back home again. There is nothing interesting or distinctive about the totalitarian society. The dramatics as Glenn Corbett tries to flee and break back in to the space centre are all typical pieces of canned action from tv shows of the era. Surprisingly, the film reaches an unresolved ending with Corbett failing to hijack the rocket that would take him back to Earth and joining a group of travellers after washing up out of the surf on a beach. Clearly, the filmmakers were hoping that the pilot would have gone to series but it never did.
Director Lee H. Katzin spent most of his career, which lasted from the 1960s to the 1990s, working in television. He did direct a couple of theatrical films of genre note with the Batty Old Dames thriller What Ever Happened to Aunt Alice? (1969) and the post-holocaust film World Gone Wild (1988), as well as the theatrically-released clairvoyance tv movie Visions (1972). Elsewhere, Katzin directed episodes of shows such as Mission: Impossible (1966-73), The Mod Squad (1968-73), Space: 1999 (1975-7) and The Man from Atlantis (1977-8). The script was from Gerald Sandford who had a five decade career working in television, scripting episodes of classic shows such as The Virginian (1962-71), Night Gallery (1969-73), Kung Fu (1972-5), Barnaby Jones (1973-80) and CHiPs (1977-83), as well as numerous episodes of and producing Knight Rider (1982-6).
One of the surprises about the film is that it is co-produced by Bing Crosby Productions, a company that had a surprising number of genre credits during this era including Willard (1971), Arnold (1973), Terror in the Wax Museum (1973), W (1974) and The Reincarnation of Peter Proud (1975). Andrew J. Fenady was a tv producer, then known as creator of the show The Rebel (1959-61) and producer of Branded (1965-6). Fenady dabbled in several genre tv movies with Black Noon (1971) and The Woman Hunter (1972), and combined with Bing Crosby Productions for the theatrically-released Arnold and Terror in the Wax Museum.
Full film available online here:-