Car shuts down at high revs

Have owned my Clio F1 since January 2014 and it still makes me smile every time I get behind the wheel. About 6 weeks ago while driving it like it was built to be driven the car decided it would shut down while I was doing about 65mph in 3rd gear then as it slowed down it came back to life with the spanner and check abs both of which disappeared after a few seconds . It happened a few more times so I rang my friend who is a master tec and has 28 years of experience of working with Renaults. He was a bit baffled and said maybe I could of overloaded the car due to having the headlights on, the radio on, the heater on full and the rear window heater on. So I tried it again the next day during day light without anything on and it shut down again. I took it to my friend who put it on Clip and it came up with no faults. He tested the battery and it was showing that it needed replacing so I did that. But a few days later the car cut out again at high revs. It's since sat in his workshop for over a month and he still can't figure out what is causing the problem. I have faith that he will figure it out because what he doesn't know about Renaults isn't worth knowing.

Just wondering if anyone else has had this problem and if so how did you cure it?
 
Were there any other lights came on the dashboard? I'm thinking along the lines of a bad earth which cut the engine off, then started again. So the lights on the dashboard would be the same as the ones that come on and go back off when you start an engine at any time
 
if he knows his stuff why isn't it fixed :eek:

as said don't over look the easiest and obvious (simple) things - to stop an engine its either spark or fuel....