Thats not what I suggested either.
I suggested we were mentally complacent. You denied the complacency and said its the formation and the player selection. I acknowledged these as factors but added that the complacency was a larger factor basically arguing that 3-0 is too bad even if its a substitutes team in a bad formation. Allegri gave the same assessment:
"I did expect Inter to cause us problems and I said many times in the Press conference that we weren’t qualified. It would’ve been better to start at 0-0, because having a 3-0 lead took something away from us in terms of concentration.
“It’s happened to me before, my Milan won the first leg 3-0 with Arsenal, then we were 4-0 down in London. It’s a dangerous situation.
“This is another part of the growth process, as when you have young players and go into games that seem easy and aren’t, you learn to do better. Inter deserve credit and we deserve criticism"
Omg, I just added player selection, formation, ref as one of the reasons. The fact that I said motivated team when describing inter should be indicative that I also think that we took this game lightly (at least less important one than Inter players did) which was also part of the problem, eventhough I think selection of the players was somewhat a bigger one. When you field 3 mids that have never played competitive game together, when you field 20 yo defender that has barely featured so far you're looking for trouble. This kind of collapse would have never happened in the CL or Serie A, since we give a damn about those competitions and players are more motivated to perform.
I've read somewhere (was it here?!) that we're mentally fragile and that just

This is a team that come back from 0-2 against Bayern, that has piled 15 consecutive wins, that has 16 wins in last 17 games in the league, that hasn't conceded for 8 games in a row...