That’s not necessarily true - particularly in the case of a heart attack. My uncle was out mowing the lawn one day, came inside the house & told my aunt he didn’t feel well. Collapsed on the bed. My aunt called the paramedics right away but the heart attack already got him & it was too late by the time the ambulance got there.
I’m not denying that sometimes it can be literally life-saving to have someone else around but there are so many things that have to align perfectly for something to go in a totally different direction.
his “wife” could have been taking a nap or inside somewhere doing laundry when he had the heart attack in the pool, fell over & drowned. Even if they had been there in the pool with him, the window when you go into cardiac arrest can be very small.