Well I've seen 52.5 bandied about on here and other message boards. It's also in the "IAAF's World Progression of World Records: 2007 edition" for all to see, if you'd care to take a look. If the IAAF can't get it right then I think caution is needed whenever so called "official stats" are published. The same book also has Ovett's last 300m in Rieti as 39.7, when it was 2 seconds slower. Aouita's 11.8 last 100 is another case in point. It was only with dvd/video recording after the fact that someone with an ounce of knowledge realised that split was taken from the 90m mark and that his last 100m was c. 13.2/13.3.
It's far and away the most reliable for finding 100 and 200m splits for the reason you give. Namely that such times are seldom taken. If the dvd pause button gives splits which correspond with known and uncontested times, then why should they not be as reliable in other instances during the same race!? In some older televised races the clock didn't always stop (as it usually does now)at the 400 and 300m from home points, yet I have found that pausing an image at such points gives identical split times as those quoted in books. I'm not saying that all splits given in reference books are wrong, just that there are always going to be misatkes made. E.g. Coe clearly ran much faster than 13.0 for the last 100 in LA, and Aouita clearly didn't run 11.8 for the last 100 in Nice 85.
How do you think tv commentators and statisticians are able to tell the viewer almost immediately what so and so ran for the last Xmetres? Because they have someone infront of a monitor playing it back.
Why do you know there is no argument over his last 300 and 400m times? Have you seen a video of this race? I certainly haven't. At least with some of the other races discussed on here there is access to the races.
I have seen wrong times (electronically) given at 1200m even in recent Major Championships. I can't remember off hand which (I'll look later), but one was in a World Champ final that involved EL G or Morceli, and the display on screen came up for the interval time at the line which appears about 6m before the 1500 start line. I can also remember a similar thing happened when EL G was running one of his 3:26 clockings. Again, I will find out which precisely later. In Moscow Straub went through 1200m in 2:59.44 (on screen) with Coe 3m back. Yet his (Coe's)1200m interval time is usually given as 2:59.5. That is impossible. Even if one argues that the time of Straub in an Olympics final was unreliable, then how can one say with confidence that one given in a less important meeting in the '60's, (with a timing to 1dp rather than to the nearest hundredth) which doesn't seem to have been televised, is 100% reliable. Most people will say, "because it's been written in books ever since". I've already shown that books aren't always entirely accurate.
Moreover, you even say yourself that some splits are broken down with stopwatches and guesses. I'm not saying he didn't run those times because I wasn't there and don't know, but excuse me for having some doubts just because a book states it as fact. Doesn't fill me with much confidence!
I disagree that he was "far too strong". Morceli was running 3:27 more than 10 years after Coe's peak. There is a lot of evidence to suggest Coe was also capable of 3:27/28 given the improvements in pacing and had he actually bothered to run enough of them. A 3:31 solo and 3:29 in his twilight, both off dreadful pacing back this up.
Of course at this stage, Ventolin (who has been conspicuous with his absence this last week;...I was hoping he'd got washed up on a desert island or something)will but in, call me a moron, quote his predictor and go on about Coe never being capable of this. No matter, I think otherwise.
On top of that, major finals, until the likes of EL G had his own rabbits setting WR pace for him, seldom went below 3:33. Straub tried to run the finish out of him in Moscow, with Coe running 1:46 pace for the last 700 (when Straub upped the tempo). Yet he was still able to increase his speed twice in the last 200 to cover the last 100 in 12.1.Morceli never displayed that sort of closing speed in any of his championship wins.
Of course, with Morceli (rather than Straub)going from 400 out, it would have been faster still and Coe would have less left, but then he was the 1000m record holder. I doubt Morceli (with an inferior 1000m) would have got rid of Coe in a championship race, and I think it would have been close in the final sprint. Certainly Coe's basic speed was superior.
Why would the Moroccans be training to employ tactics to beat Coe when he had long since retired?