I wasn't intending to fool anyone, that was the truth!

that said, maybe it was FGW's April Fools joke to passengers on that train! (Just kidding, it usually is good!

). It didn't originate at Salisbury, that service is the 1728 Warminster- Great Malvern evening stopper. It starts from Westbury to serve Dilton Marsh, terminates Warminster and usually hangs around on the track south of platform 2 for 10 minutes, but in this case it was only there a few minutes before coming back to platform 1.
I must say though, it was much faster than normal!