The reality is that the RAF operated this aircraft/ejection seat combination for nearly 40 years before the accident occurred, and during that time there were successful ejections from RAF Hawks, so it seems unlikely that the failings were due to unfamiliarity or design flaws. Somewhere along those years personnel 'lost' their full understanding of operational and maintenance procedures. When, or if, changes were introduced processes should have been in place to review and understand revisions so that any re-training was effective and new requirements were safely applied.