While I don't agree with the practice, when I was younger it was very common to see civilian hunters use the half-bent position on Lee Enfields in the manner described by Cinders.
Their "folklore" reasoning was that safeties are not to be trusted.
My thoughts were if you cannot trust the safety and the sear, why are you hunting with a defective rifle?
I think this was woodsey folklore and adapted practice from the other common hunting rifle, the Winchester 1894, which had no dedicated safety only a half cock and grip safety.
Over the years I have seen all manner of workarounds, and mechanical superstitions to excuse the root cause in nearly every case: poor weapons handling.