This is allegedly a Canadian-British co-production. In Canada, A Man Called Intrepid first aired on CTV on three consecutive days starting on May 7, 1979. But how was the series first released in the UK?

Also, there is allegedly a theatrical version that was released in a couple of countries at the same time. If this can be confirmed, it should be added to our list of exceptions.

I don't understand... You by yourself say that this is a TV mini series indeed! Three days = three episodes. So what's your problem to change it? Did I say something on my report about UK? By the way, a possible dublicate is this one and you should delete it: https://www.themoviedb.org/tv/25686-a-man-called-intrepid

I need all the information before I can make an informed decision. So we need to find out how it was released in the UK, and when/where the theatrical version was released.

What do you mean by "how"? You see for the first time a co-production between different countries, which one of them released first with the form of a different production category? A more "recent" example is BBC/Canadian production of "Torchwood: Miracle Day". Things are simple and you shouldn't make them more complicated. This is a co-production that was released as a TV series in U.K. and afterwards it was released in Canada. You should record the first air date and only that one in production category that was. Next releases in any country, in any form and category, are irrelevant and just data (or just trivia) that anyone could register afterwards. That first release date defines its production category in this and any database.