"Saved by the post" is one way of looking at it I suppose.
But the other way is this. They are a very good side very early in games, putting furious amounts of energy into it all, doing a load of closing down and everyone sprinting all over the place. The goal was an error but they can claim their pressing was part of it, and it was. They often get an early goal.
But no team can ever keep that up. Sheff Utd at Wembley? Same thing. Southampton under Poch? Same thing. There have been plenty of others.
You pay for that type of running and for rushing that high up the pitch so much. They often run out of gas, and they ran out of it again on Sunday, leaving the gaps we were playing in, including the winner, which, the more you watch it, was a very clever goal indeed, after they had given the ball away yet again, a sign of a team with a lot of good runners but few real footballers.
The team who has lost more points from winning positions lost to the team who has won most points from losing positions. 2-0 might have been enough. But it might well not have been.
It's not "all these games" they play that has them bedraggled so often late in games, the same was happening early in the season. It's the way they play them.