Most of my drinking was done in isolation so therefore most of my blackouts were just me as well but there were some that others were there for. For me there was always just a shadow of a memory so if somebody told me something it usually either had a ring of truth to it and would prompt me to maybe remember some tiny little something to tie it in or a bruise or something to back it up but I have a friend who for some reason loves to exaggerate things and swears things happen a certain way when I know for a fact they didn't because I WAS STONE COLD SOBER so if I didn't have that little shadow of a memory to jibe with what she said I did then I am pretty sure it was either BS or so grossly exaggerated that it no longer resembed reality.
I hope you find out what you need to know, I guess blackouts are different for all of us as some have no recall while others may have a shadow of a memory.
Good luck!
Kellye