I suppose that is the problem with owning your own machine with a low level of experience.
If you self fly hire from a club, an instructor has to authorise your flight (at my club anyway). This means if you are planning a trip of that distance (chelmsford - kinloss, in this case) your planning, fuel calcs, route etc will be reviewed, thus preventing any gross errors. In addition to that the majority of clubs have 30 day (there abouts) currency requirements, which is also effective in picking up rusty areas etc.
In other words you have someone with a greater level of experience 'keeping an eye on you'. Which was probably lacking in this case - although nobody can say for sure.
I am not saying that low hour pilots should not own aircraft, but it does remove this safety net......... the debate continues.