the tuner set the parameters too low, not the car is getting too hot. i had the same thing happen the day after getting tuned. called the tuner while at the track to figure it out. i was being limited to 7800 rpm at 210* lol

 

Its easy to check and change this setting. Just hook your PC up to the Haltech and turn the ignition to ON. Start up the Haltech ECU Manager software, press the connect button to view your current map settings. Then scroll down on the left to find "Limiter" section and choose "Rev Limit". You'll see the plot of RPM limit versus coolant temperature here. The screenshot below is from the standard S2000 base map that Haltech gives you. Its likely your tuner never altered these settings. Since you have an 01 you can set this to 9k up top as long as you're confident your tuner has set up adequate timing/fueling settings under high coolant temp situations.