Im sure it was.

25 miles at 75mph?? IMO...that is a tire that was almost surely over heated.

One of the reasons mfgs tend to recommend replacement is most rire shops cannot/do not understand tire damage. It is hard to ascertain when the carcass has been damaged due to overheating.... safer to say 'we wont repair a runflat that has been driven on'

why would you drive on a runflat and ruin the tire, when a spare and a tire repair can save the tire?