Ive seen the same hearsay but am skeptical. I was there. 86259 first ran southbound at preston to try and cross the line and couple, but was instead sent back to platform 3 due to a points issue. Then it went northbound, back and passed us on the road to the left of us where we were waiting , then was stopped for a very long time for another points failure to be resolved.
This more suggests some problem with the electronics or the signaller for preston.
Note that once the issue was resolved we was allowed to go, which doesnt seem likely if the crew of 86259 had SPADed and destroyed 2 sets of points.