In this match, I expected a draw just like you, and Brazil losing was both expected, but I was confused about these two options. However, Argentina brought me out of my confusion right at the beginning of the first half of the match and I could pretty much guess in the first half that Brazil would lose this match and that's what happened. To be honest, I don't have much expectation from Brazil for the next World Cup this time.
I also didn't imagine we would see this result. I knew Argentina was the favorite, and that they would probably win, but I expected something like 1x0 or 2x1. When I opened the video start watching the match in real time, it was already 3x1 for Argentina and it was still the beginning of second half.
Brazil got really lucky, because the result could be much worse yet, with so many shootings from Argentina directly to the goal. It was the worst result for Brazil in the history of qualifiers, and yesterday's game now belongs to the worst moments of brazilian soccer, side by side with the 7x1 for Germany in 2014's World Cup.