Let me put it this way:
If you are right in the middle of the enemy's jungle with no wards...
If you are pushed right up against their turret with no wards...
If you are attempting to roam between lanes with no wards...
If we have no clue where the enemy jungler is...
If I am playing an immobile, squishy midlaner with no reliable way of getting away from a possible 2v1 which has a 50:50 chance of occurring short of burning flash...
AND I PING TEN FUCKING TIMES THAT MY LANE OPPONENT IS MISSING...
IT IS NOT MY FAULT IF YOU GET CAUGHT OUT BECAUSE YOU REFUSED TO WITHDRAW.
If I pinged only after my laner was gone for a good ten seconds and by then it's too late, or if I was two feet away and refused to cast a spell, or if I was sitting in lane waiting for the next wave instead of trying to ward to cautiously find where my opponent is, or If I was clearing minions when you had a prolonged get-away that I had plenty of time to help with, including proper positioning, then yes. It was my fault. My bad. I apologize. I shouldn't have done that.
BUT.
If you think that I'm to blame just because you died from a midlane roam, then I don't know what you think you're doing.