Script Writer of Terrible Dream Story!

What was the incident? 

Just a little lateral thinking required to crack that puzzle.

If that brother was died immediately after his brother put hand on his shoulder then how who wrote about his dream in detail? Hence the incident of death due to massive heart attack is totally fake one! Only possible way to know anybody about died brother's dream is the died brother himself coming in his dream & tell the entire story of what happened on that night.