Rochdale, who avoided the relegation trap door for another week, were second best for 79 minutes thanks to a first-half penalty from Daniel Nardiello and Liam Sercombe's strike after the interval.
But Tisdale's men suffered an alarming collapse once Nicky Adams pulled a goal back with 11 minutes remaining. Joe Thompson levelled things up before Jason Kennedy slipped the winning goal beneath Exeter goalkeeper Artur Krysiak to keep Dale's survival hopes alive.
"The way we played was more top three than bottom three and all we had to do for the last 10 minutes was stand in the right place at the right time and think the right things," Tisdale said.
"I can do no more. We had played so well and all we needed to do was some simple things. But no matter how well you play the other team are entitled to have an attack and anything can go against you. When that happens you just need a cool head, but we found that very difficult.
"I'm very disappointed because we were brilliant for 80 minutes, but the result counts over 90 minutes."
