I wasn't there, and have never flown a Tiger Moth. I also would treat anything heard so far as hearsay.
But, 300ft on take/off from Compton Abbas? If the engine did stop, you're on top of a hill, and a gentle northerly turn should take you down into a valley with a reasonable number of options. Most days you are taking off on 26
(Convenient photo found on the interweb. 9 years old, but looked pretty much identical when I flew in there last month).
Yes, turnbacks from low level are highly hazardous - although actually seldom fatal. The vast majority I have investigated have written off the aeroplane, and caused significant injury, but
usually not loss of life.
G