Very simple test even without the EOG speedometer would be to check speed in ER and NR. If both are showing 140, then it is almost definitely error of GPS app. No LP over speeds on purpose. Rajdhani LP are experienced old hands. They don't get any thrills by over speeding. And regarding trials, they can be done on passenger trains without any public notification. Eg During push pull trial there wasn't any public notification. Whatever it is, no rules are being broken. Poorva at 140 is definitely a hoax though.