Prost - Renault relationship

[Antonov]

I realise this may not be the most straight-forward question;

How come that after Renault blamed him for everything at the end of 1983, they wanted him back (as an engine) in 1993?

[Michael Ferner]

Someone at Renault may have started counting, like number of wins before and after Prost left.

Seriously, ten years is enough to realize a serious error of judgement, isn't it? Ten months probably already did the trick, but pride stands in the way sometimes.