Nobody will be surprised at this. Firstly - sheer weight of averages meant that LHR was overdue for a significant ground incident of this kind.
Secondly, the 100% change in corporate attitude, in recruitment, in training and everything means that we will see more of these incidents. AND because theses one ran away and because they have arrested them - the next guy who bashes an a/c will be more likely to run, than to report. CCTV will not make them stop and think.