Flungdung,
Whilst I do agree with you re the definitions, consider the following...
The scenario...
On an IFR departure with cloudbase between 50 and 100ft, vis 150 -200 metres and the nearest single engine diversion almost an hour away (all legal for North Sea Cat A ops).
The problem...
Just after TDP, but before going into cloud, with the runway ahead of you still visible, you have an engine fire warning, would you continue the take-off, or put it back on the ground?
I'm sure I know what I would do. If I could get it back on the ground that's where it would go regardless of any 'legal definitions'.
Brom.
All this discussion only applies to OEI. All other issues, problems, emergencies are a seperate issue.
This what happens when we use airplane logic/regulations and apply it to helicopters.