The first steps towards hovering using jet engines for direct lift were all taken by the RAE Farnborough. In 1951 they instigated a model rig test of a jet reaction attitude control system. The success of this led to them contracting Rolls-Royce to build a man carrying hovering rig called the Flying Bedstead which flew in 1954. This in turn led to a contract on Shorts to produce the SC1 aircraft with four separate lift engines plus one for propulsion to investigate the transition manoeuvre. A double transition (accelerating onto the wings and back again) was achieved with the SC1 in 1960. Later that same year Hawkers started to use the P1127 to look at the notion of jet lift (initially PV) using a single engine with swivelling nozzles. This was a less complex way promising greater reliability when compared to the SC1 but the penalty was it relied on the pilot to correctly operate two controls with the left hand (throttle and nozzle lever)
Clearly if you accidentally close the throttle or raise the nozzles when in the hover the thing will fall on the ground. People make mistakes. Whether they recover from them depends on many factors. I accidentally closed the HP cock (so shutting down the engine) at the start of a decelerating transition on one occasion. The dying whine woke me up so I relight the donk and gave myself a talking to.
Even though today they are operated by six nations and have been in service with the RAF since April 1969 there is still much rubbish written about them by people who don’t do their homework – or in some cases even think at all before they post something. Sorry, rant over. I need my breakfast.