After clicking "OK" in the "Adventure Tips" window that opens after defeating the last enemy, the game counts the level as completed even if it has not finished displaying your berries/exp/rewards earned (tested with blitzes and other events that have a website with points). So yes, if you click "OK" before you have to pray that nothing happens.
On a side note, before events like Kizuna/TM/Blitz start, disable 1-wave the day before. This worked well for me as I am from Europe and those events always started in the middle of the night for me so when I closed the game in the evening I would disable 1-wave and the next morning I could play without worries. It's a habit you have to develop so next time something similar won't happen.