True but a vistiting aircraft needs more observation & care than a locally based aircraft, especiually where a non standard procedure exists, as this accident proves. Accidents are usually the results of error chains despite people not being able to understand that chain. Admitting the existence of the chain rather than a single cause can improve aviatiion safety. This is not the first time this type of accident has occured in a circuit (Hamble early 70s) without ATC.
An aircraft had just taken off at Shobdon with another joining surely this warrants some special visual attention from those charged with the safety of the ATZ traffic