The problem I have with posts like this is that it seems that by filing a NOTAM, than some people think that actually establishes protected airspace. Unless it is an RA(T) then the airspace remains class G and ALL pilots, including though involved in aero's are allowed acces and are required to see and avoid and comply with the rules of the air. There is no requirement to contact anyone, and being VFR *visual* flight rules *ensure* separation. So as far as I can see, no rules have actually been broken and no action could be taken.
Maybe on the other side of the coin perhaps there should be a requirement that ALL aerobatics should be Notamed and protected airspace established as an RA(T) or dedicated aerobatic boxes established? - That is overkill IMHO but could be the result of too much complaining or too many "busts"? In the USA you often find dedicated aerobatics areas on the charts.
However, it is stupid to not check your Notams, or not understand them and one would be prudent to keep well clear, but I don't think it is criminal negligence. The phone number is just "airspace upgrades" and RA(T)'s and won't list an aero's comp. A useful graphical tool like Skydemon shows notams very well, something which AIS should consider.