Loading game while alt tabbed

While loading I instantly hit alt tab and after maybe 1-2 mins I tabbed back seeing where yasuo was loading since his was slowly loading. All of a sudden after the yasuo loads in completely I load in to a Defeat screen with me being at fault for afking when I never loaded in at all. Is this a known issue? I'm going to have to not alt tab anymore on long load in to prevent this from happening again.