Ron Dennis prided himself on his integrity to such a degree that I cannot imagine him sanctioning anything like that, nor would he want to win that way, by obtaining detailed technical info on a competitor and effectively cheating.
Had he known about it earlier, he'd have done something about it.
Hehehe.
So in otherwords, what you are suggesting is that R.Dennis didnt even know what the hell his own employees were upto, while they were on company premisis, using company equipment? Perhaps he really was that naive and stupid, but I doubt it.
On the day that Alonso made the threat, it was a throw away comment that he made while walking to back his motorhome, after (a controversial )Hungarian GP qualifying, when R.Dennis was having a go at him for what happened during the qualifying session.
Alonso, flippantly told him to get lost or he will tell the FIA was the team have been upto (regarding holding Ferrari technical data). R.Dennis, knew exactly what Alonso was talking about and from this point onwards hardly spoke to Alonso and didnt interview Alonso to find out what he was referring to. R.Dennis then reported his team to the FIA.
Take note that he didnt ask Alonso about the emails, which Alonso was talking about in his threat. Dennis didnt need clarification. He knew exactly what Alonso was talking about.
Dennis knew exactly what was going on. And so he should.
F1 is corrupt. It is full of dodgy people, namely due to the competitive nature of the sport and the sheer amounts of money involved. All teams want to win,, sometimes, even if it means winning in an unfair manner. I have no doubt that if Ferrari had come by McLaren data, that Ferrari would also have taken a detailed look, to assist their own car development program.
Personally, if I was a McLaren employee and there was a big fat document with Ferrari data/diagrams on it, I would 100% take a look at it. I don't see anything wrong with this. Now, what N.Stepney did (as a paid employee of Ferrari), where he handed over data to a rival team: this was out of order and totally dispicable.