I have been in a situation where I boarded a plane without any valid visa.
(Long story, but it was a three-leg flight A–B–C, sold as a two-leg flight. The first two legs A–B shared the same flight number, same airplane, same boarding pass, same seat, but the second "leg" B was a domestic flight, so I had to go through immigration.)
My impression is that it is partly the responsibility of the airline to check the validity of the visa before letting you board. In my situation, I had to sign a form, saying that I would buy my own ticket out of the transit country, in case I couldn't proceed through immigration to board the domestic flight.
Strictly speakingIn your case, the airline does haveprobably has the right to deny you boarding the plane, but since they can see you have a valid visa 5 minutes after you are scheduled to arrive, I would strongly suspect that they will let you board. Their worry is to take a passenger, who will be stranded in the transit zone, because they don't have a connecting flight, nor a visa to pass through immigration (in which case they might be made responsible for taking youthem back).