Okay, I'll bite. Again.
There have always been two counting methods for the DALLAS seasons. Old TV GUIDEs and CBS press releases have always reflected this 14 season count-- but even TVGUIDE was inconsistent (or, at least, ambivalent) because when DALLAS ended in May 1991, the magazine referred to "13 years" (not 13 "seasons") on the cover while still continuing to use the "14 season" count inside the pages. (And DALLAS had, indeed, run 13 years and a month)
DALLAS' 5-episode "miniseries" (as the cast and fans usually call it) was, in fact, originally intended to be a 5-episode pilot of sorts, airing April 1978.
That was followed by thirteen
full seasons.
And this is where the confusion begins: Because the miniseries/5-episode-pilot aired near the end of the 1977-'78 official TV season, and is thus separate from the 13 subsequent full seasons, American industry standards consider that miniseries from April 1978 to be "Season 1" (and always has, as reflected by CBS press statements and the inside of TV GUIDE) despite its brevity. (Find a copy from November 1980 and it tells you, in the DALLAS listing, that the series is beginning its "fourth season" as opposed to its third -- and refers to it in this manner, using the 1 thru 14 count, throughout the program's run.... regardless of how that final cover in 1991 phrases it).
So it creates conflict. And it can confuse fans as to which year one is referring.
But some folks get their back up about the topic, insisting -- or believing -- that the 1-thru-14 count only began in 2004 when the DVDs started coming out, accusing Warners of "changing" the count blasphemously for cynical marketing purposes (which isn't really true at all .... not that they're above doing so, of course).
One site member here even felt the need, years ago when the topic came up, to insist that "CBS later apologized" for the "erroneous" 1-thru-14 count (which that poster completely made up in order to "prove" his point in defending the miniseries-thru-S13 count he'd preferred).
Some of us enjoyed a good laugh, and a fine time was had.
Anyway, for further clarification on the issue, we could ask
@Barbara Fan .