I can't help but think this was a foul up. On
SWT▸ 's facebook page someone complained on 31 October about the SW Summer 25% off in relation to the return restrictions from Waterloo which had been purchased from a
TVM▸ . As you say, the last 2 major promotions (50% off half term, 25% off Fri-Sun in September) were never meant to be available from a TVM.
However, the first one which ran this year every day from 21 July - 22 August offering the flat fare of ^15 was under the banner of route "SWT Only" where it was available from TVMs.
http://www.stagecoach.com/media/news-releases/2014/2014-08-15.aspxJust speculating, maybe the recent 25% off fares were loaded to the TVMs and somehow remnants of the earlier promotion remained enabling that option to appear.
Secondly, I think SWT maybe have forgot about fares involving Reading -> Basingstoke operated by
FGW▸ which again, I am guessing would need to be manually excluded (akin to the Bristol fares on the earlier promotions, apparently they were going to sort this out for Bignosemac on the half term promotion). Again, as you say no sensible route exists "SWT Only" in this scenario.
...so in my view it was at least 2 errors!