Unforgivable?

[Mathias Forseti]

No: HPFGUIDX 153219

Alla:
>> Um, THAT is an incident that truly deserves investigation, because
Harry used an Unforgivable. I mean, I am pretty confident that very
good case for self-defense can be made, but Unforgivable had been
used and the letter of the law demands investigation, IMO. <snip> << 

BAW:
> Erm, when did Harry use an Unforgivable in that scuffle?  As nasty 
> as 'sectumsempra' is, it isn't an Unforgivable.  <snip>

Mathias:
I'd think that even an attempted use of a Unforgiveable should be 
investigated, but the Sectumsempra isn't an Unforgiveable, its just 
a curse.