Weird scenario??

Me and a friend were playing amateur, we found the room at least we thought to have, there was a low temp on the staircase to basement (Tanglewood btw) and in the first min of the game when I went down the stairs the emp went off like really loud, then it disappeared that's the first question, Why'd it sometimes goes off like that than just goes away

2nd point, I then found a oujja bored, I asked where the room is.... The living room, said goodbye gave it to my friend, he was trying to ask where the bone was , then I think a hunt started, friend panicked threw away the board without saying goodbye, got killed then the ghost went for me as if he just didn't kill my friend a second ago, was running around the kitchen island, he was fast, realized it was a mare , he caught up and strangled me? (It was a mare)

I thought that only on the highest difficulty the ghost can kill more than one in one hunt?