He may have been better off staying on to Camborne, walking to the bus station and travelling on to Helston on the 39.
The First-run "Helston branchline" bus service isn't worthy of its name: services are often timed to arrive NOT to connect with non-FGW▸ train services and if you're arriving in West Cornwall after 6pm and need to get to Helston, your only hope is to stay on until Penzance and get a bus back to Helston from there. Over half a century ago, a prairie and a B-set would have been waiting for you at Gwinear Road at 7.45pm and 9.25pm.
Or indeed the 45 now. There are now 2 buses an hour from Camborne to Helston for most the day.
The bus service hasn't connected with trains for years now, since the timetable was changed from one providing connections with trains to a regular hourly service, which is more use locally. The loss of evening services is fairly recent too, a victim of the funding cuts as a result of the current governments policies.
Passengers holding through train tickets to Helston may also change at Truro, although that is probably of little use nowadays. The Helston-Truro link has been cut from 3 buses every 2 hours to just 1 every two hours. Even then the bus departs from Truro bus station, a ten minute walk from the railway station. It may be of more use in the evening though, the last couple of buses start back from Truro railway station, and they are later than the services from Redruth. The last 34 from Redruth to Helston departs at 1820. There are 2As from Truro to Helston at 1910 and 2110.