I have heard in a talk given at the Fermilab (on Youtube) that we typically detect a neutrino burst from a core-collapse supernova CC SNR explosion 2 hours before we detect its electromagnetic radiation. When the question was raised about whether this violates the principle that nothing can travel faster than light, the answer given by the speaker was that when the collapse is happening, the neutrinos are expelled, whereas light from the supernova comes AFTER the explosion, not during the collapse. But doesn't it take about 1 second for the iron core to collapse completely? Why is there a 2 hours difference between our receiving the neutrino burst and light from the explosion?
P.S. I read around and found that the reason is because light has to travel a lot of distance within the star which "slows" it down, however, as mentioned earlier, it takes only 1 second for the entire iron core to collapse, right?