As you have said that shouldn't be. With teams at thay level it should be a game that is closely contested. Realistic blow outs in the Champions League are around 5-1 or 6-0 unless you meet an extremely weak team. Well blowouts are more common or should be more common in the group stages and not during the knockouts.
I just played Champions League RO16, and I'm playing away and lost 3-1, but I beat the team 3-1 at home. I'm at 90% and he's at 79%. Losses can happen at that difference but the stats don't show up. I was there form the start of the game and he wasn't.
Tactucs: 4-5-1V vs 4-5-1V
Possessions: 25 vs 75
Shots: 16 vs 24
Shots on target: 6 vs 10
Completed papsses: 80% vs 85%
Corners: 4 vs 9
Saves: 5 vs 1
Red cards: 1 vs 0
That guy nearly did a comeback on me in the RO16. Lol!!!!