When they stay at the Parador, that is actually the Parador in Santiago. The next morning they are seen walking past a sign saying 'Santiago 222 kilometers'.
This is not an error at all: The Parador shown is the one in León, at around 320km to Santiago. The sign "Santiago 222km" is at Manjarín, a few kilometres from the Cruz de Ferro, which they passed therefore 3 days after leaving León.
There are shots taken in the village Briñas. Briñas is not even on the Camino Frances, being too far north to be on the path.
While it is true that Briñas is not on the Camino Francés, it is on a recognised route, the Tunnel Route or Camino Vasco, from Irun, which joins the Francé at Santo Dommingo de la Calzada.
At 50 minutes in, Tom is with a group of peregrinos and talking to Father Frank (from New York) when they pass the church of Santa Maria de Eunate on their right, which means that they are not on the Camino Francés, but walking northwards towards Obanos.
When Tom starts his walk you see him come through the archway near St Jean-Pied-de-Port's Church. He turns left and then the Captain Henri corrects him and tells him the Camino starts over a small bridge. Neither Tom or Henri's route are actually on the Camino which should run straight over the River Nive directly from the archway and up the Rue D'Espagne out of town.
Tom and company are shown with backpacks in Santiago Cathedral, but pilgrims are not allowed to take backpacks or large bags into the Cathedral. They also enter the Praza Obradoiro before going into the Cathedral from the wrong direction.
At the end of the first day we see Tom coming into a huge refugio. This used to be the original medieval hostel in Roncesvalles called the Itzandegia (no longer in use). However in the film he arrives at La Posada and all the outside shots are used here, but this is a Spanish hostel with only single and double rooms in.
On the first Day of Camino we see Tom pass the statue of the Virgin in close proximity. In fact the statue is 100m left of the route so the shot is clearly done for visual effect. It would be impossible for him to come from that direction as there are sheer cliffs there.
Filming some shots after Roncesvalles, you can clearly see Tom sitting outside the Hostel at Orisson. This is in fact 8km from St Jean and before Roncesvalles so in completely the wrong direction. Opinion: There is no suggestion that Tom was walking in the wrong direction, simply that the location was shown in the wrong order.
The pilgrims visit the Albergue Casa Santa Barbara that they say is in Torres del Rio. There is no such albergue. You also hear Tom say Torres is the next town which is not correct. Sansol would have been the next town as this is only 1km before Torres, and the two are almost interlinked.
After leaving Torres, Tom and company are seen to be camping as they say there is no albergue for 4.5 hours - even at a gentle pace this would be around 18km walking. In fact the next albergue is in Viana, a 2-3 hour walk.
At the end of their Way, the four pilgrims directly go to the Cathedral, carrying their backpacks. This is not allowed, the bulk being an annoyance when there are too many people inside, and also for security reasons.
Somewhere before Pamplona we see Joost go on while Tom stays at a small village with an albergue with an outside meal where he meets Sarah for the first time. There is in fact no village or albergue between Roncesvalles and Pamplona that this could be. The village would have to be Zubiri or Larrasoana, neither of which look like the filmed location. Correction: The village is actually Akerreta. It is on the Camino. The camino goes right through the village and passes the albergue which you can see on Streetview.
At 1:44 (approx) they are leaving O Cebreiro (Tom and Jack pass a sign that says only residents can enter the village in cars -- you cannot see enough of that sign to read it in the film, but Streetview will let you have a look at it). At 1:45 they are walking along the paved road at O Cebreiro, with a low wall on their right. Again they are walking in the wrong direction.