The manual says to put 98 in it, but also says it san be ran for short periods of time on 95 when 98 isn't available. Apparently the knock sensors aren't very accurate after 5000 RPM and this is where the problem stems from. I'm sure there are plenty of cars running 95 and haven't exploded yet, the ROI guys are testament to this, but I prefer to follow the guidance of the manual to lower the risk of future problems.
HR 350Z's and 370Z's don't have any problems running on 95 because their knock sensors work throughout the rev range.
I'm far from an expert, but I'm sure Mark@Abbey would be happy to explain this again and he has done many times in the past.