"this is a peak time train" was certainly said
"off peak tickets are not valid" was also certainly said
There may have been a conjunction ('and' for example) between them, and the "off peak tickets" may have been followed up by "on this train", I wasn't quick enough to record the announcement. It was a manual announcement by the guard.
I wonder if it's the same guard ALR mentions here (this was the 0930 ex Crewe)
That's not VTWC's interpretation. When on a day out to Manchester a few years ago with two children in tow, the train manager on the outward journey refused to accept that SOR (Standard Anytime Return) tickets were valid in first class on a Pendolino on a weekend (a concession that VTWC has offered for many years). After politely and calmly explaining why the tickets were indeed valid, and eventually deciding to stop talking when I could see the conversation was going nowhere, the train manager said that the BTP would be waiting for us at Manchester Piccadilly. Unsurprisingly, the BTP weren't there. I'm sure the train manager involved was the same one who regularly claimed that the 08:29 Crewe to Euston (07:55 ex. Manchester) is a "peak train" and refused to accept off-peak tickets from stations in Wales.
It is normal behaviour on the WCML. This isn't a one-off. This isn't even a guard getting VK and VM confused. Vrigin operate a systematic attack on people using off peak tickets. Not just guards, not just barrier staff, not just team leaders, but also "Dave", who is apparently the oracle of Euston.