if you have never had a problem with clutch slipping at all before this
then it is very likely( especially you are prepared to admit to pulling away a bit too quickly )
that the circlip inside gearbox has jumped out of groove causing differential to seperate and loss of drive
this can be checked (and replaced) by removing nearside drive shaft after draining oil
circlip and washer is about £5.00 from renault dealer
this is acommon ocurence on all transverse renault boxes ie clio laguna 5 19 etc
only caused by smoking tyres etc
get a 2nd opinion by a local mechanic