He actually has a pretty good point.
Assuming both planes started at about the same airspeed and took off from relatively close aircraft carriers (let's face it - who in their right mind is going to fly a TBM as far as they would a B-17 or Lancaster? Usually the TBM comes into play when the fight is relatively close quarters, like during carrier battles and airbase captures), then both planes would be low and fairly slow. The Hellcat may not see the TBM low on the deck until he's already passed it on climb-out from his own carrier, in which case he would be chasing the TBM from behind and slowly gaining ground. Using a bit of rudder, the TBM pilot would force the Hellcat to use deflection shooting, and even though a single .50 isn't a match for six guns, by concentrating fire on one component that single .50 might be all it takes to saw off a wing or stabilizer. Plus, that single .50 would have a longer reach since it was firing "downwind" while the Hellcat would be firing "upwind".
If the Hellcat pilot took the time to get alt and airspeed for a front-quarter shot, that TBM might be in position to loose a torpedo at the carrier.