?
A ticket was purchased from Manchester to Stockport on Sunday 10 January 2021, at 14:27, and from Bedminster to Bristol at 18:13
That suggests an arrival in Stockport around 14:39.
Google Maps suggests that Stockport to Bedminster by car takes pretty much exactly 3 hours, so that would be arriving at 17:39, which means that if in fact the Op had some errand in Bedminster, which they might well have done, then there would be time to complete it before taking a train after 18:13, possibly the 18:40 (it's an hourly service at the moment, no idea in 2021).
It also makes plenty of sense that if one were sharing a lift, one would prefer to travel from the outskirts of Greater Manchester, not central Manchester
Bedminster isn't between Manchester and Bristol TM, so a hypothetical "sandwich man" would also tend to buy a ticket from Bristol Parkway to Bristol Temple Meads, not from Bedminster to Bristol Temple Meads.
Bedminster is about £1.20 cheaper than BP to BTM, which would provide some motive to buy the Bedminster ticket, but not a great one given that none of the rest of the travel suggests shortfaring, nor indeed have the TOC suggested that he engaged in this.