Have it figured out, assuming all teams took the same flight as was presented on the show:
The ferry was scheduled to arrive in Trondheim at 6.30am on 19 Jun. Have to assume that teams didn't arrange for flights that left Trondheim before this, even if the ferry ended up arriving a little early! It's 30min to the airport and 45min to check in before the flight, so teams wouldn't have booked anything leaving before 7.45am.
A photo of a team posing was posted at 2.08pm local time in Gdansk. Taking off 15min to exit the airport, 23min for the ride via Solidarity Square to the Golden Gate, and another 15min to walk to the Neptune Fountain and get dressed, the flight arrived no later than 1.15pm.
The only itineraries that fit this are routings via Oslo. There are multiple options for each leg, however, but our analysis precludes teams transferring via Copenhagen, meaning Wikipedia is more than likely wrong (shocker!):
SK 343 from Trondheim to Oslo, 0750-0845
DY 747 from Trondheim to Oslo, 0800-0855
SK 345 from Trondheim to Oslo, 0820-0915
DY 749 from Trondheim to Oslo, 0830-0925
DY 751 from Trondheim to Oslo, 0920-1015
SK 347 from Trondheim to Oslo, 0920-1015
DY 1052 from Oslo to Gdansk, 1100-1225
SK 4789 from Oslo to Gdansk, 1120-1250