It is interesting is it not that now Nicholls has decided that he has been overracing Kauto Star ( should not have run him in the Betfair )and is limiting him to 3 runs a year !
As for Best Mate whilst it is of course possible that he bottomed himself in the soft ground GC of 2004 he had of course had to battle hard to win his KG under AP against Marlborough and had always given his all.
Furthermore, his virus picked up when going over for the 2004 Lexus was well documented was it not at the time , he also had all those staples in his head , he pulled a muscle slipping after jumping the first and the race was run in a bog against B or S at the height of his form ? So he ran well if he wasn't trying !
The Exeter race might be less easy to explain as he should indeed have beaten Seebald much more easily , it was however first time out , Murphy was riding rather than Culloty, and they didn't go much of a clip .
Moreover , though I suspect BM was indeed known to be much more fragile than it ever seemed when he appeared on the racecourse if they had believed he was at any risk in autumn 2005 they would have retired him . Indeed Brian H after the death of the horse , on here I think, mentioned that he had been working very well including in uphill gallops and that they were pretty excited at Wantage . Hence , whilst it may well be that they knew he was fragile and he might well have bled I very much doubt there was a heart problem they kept from the public.