The reviewer does not specifically conclude that the Fynes BEAT the LS50s. His review is quite balanced, and he avoids making absolute statements by focusing on the different characteristics of the two speakers, also making reference to partnering equipment.
I haven't heard the F500s, my experience of Fyne Audio being limited to my Dad's F302s, which are excellent compact floorstanders. That being so, I am unable to comment specifically on Fyne Audio speakers, but I can draw out some salient points made in the review with reference to my own experiences of the LS50 Metas.
The reviewer makes reference to the exposing nature of the LS50s, and I would agree that they do not flatter poorer recordings. The level of detail and insight they offer is a significant factor in how well they reproduce beautifully recorded acoustic music including artists such as Natalie Merchant, Diana Krall, Cara Dillon and Martin Simpson. They also do a great job with electric albums such as Mock Tudor (Richard Thompson), The Courage of Others (Midlake) and The Sophtware Slump (Grandaddy). Small-scale jazz and classical music also sounds great - Oscar Peterson Trio, Charles Lloyd, Beaux Arts Trio, and even the Menuhin/Kempff recordings of Beethoven works for violin and piano.
There are issues when turning to less well recorded albums such as Liege & Lief (Fairport Convention), and they do head into some problems with larger-scale recordings such as Mahler symphonies, some operatic recordings and quite a bit of progressive rock. In more complex mixes (Eg. the latest Fish On Friday album), voices can occasionly become overly recessed. My B&W 606s communicate the music from these recordings better, similarly to how the reviewer describes the Fynes, and that's one reason why I'm currently taking a break from the LS50s in their favour.
Some of this also comes down to how exposing the LS50s are of partnering electronics. The reviewer makes reference to the Marantz MCR-611, which I know very well. This would not make a good partner for the LS50s. It's a very talented all-in-one unit and can sound very persuasive with a good range of speakers, but it doesn't have the power or resolution to provide what the KEFs need. Even my fairly powerful Musical Fidelity and NAD amps aren't quite up to getting the best out of the KEFs, and that will be a contributing factor in some of the issues experienced with larger scale recordings and complex production.
No speaker is perfect in every situation, and it ultimately comes down to which compromises you're most prepared to make. Nobody is pretending the LS50s (in whatever version) are perfect, and neither is the reviewer slamming them or even expressing an opinion that the Fynes are absolutely better.
As I've said before
@Surly Sid, I'd be fascinated to read your direct experiences with reference to musical examples. It would give us a far more interesting idea of your own viewpoint than simply sharing videos that you interpret as supporting your hitherto wild claims.