Yes, it's true that experienced circle makers can construct formations whose man-made origin is undetectable using photo analysis. And some formations might be so skillfully devised that onsite detection of such fails as well. All that goes without saying. Despite this, it is still the case that Nancy Talbott examined crop specimens from formations easily discerned as man-made, and determined their abnormalities were most likely caused by hypothetical plasma vortices. This gives "blind sampling" a whole new meaning.
Doug
While there's nothing wrong with checking an aerial photo for construction flaws that could be attributed to people, if by implication a 'flawless' crop circle is assumed to be 'genuine' (i.e.
not man-made) then the methodology itself is flawed for the simple reason that man-made circles spawned the very aesthetic
– symbolic design, precise edges, a smoothly flowing and layered floor, etc – that defines the genuine. Nowadays, that is. The fact that crop circles gripped popular imagination based on comparatively simple messy circles shows how much subsequent analysis has been a slave to fashion.
(I'm not suggesting that that's what you're implying Doug, but many others have been quick to make that leap.)
In critiquing B, L & Talbott's work, it's worth bearing in mind that it wasn't them that hypothesized the Plasma Vortex – that idea was hijacked from Meaden, a real doctor, just as they hijacked the concept of swollen, bent, and exploded nodes as an indicator of genuineness from Kay Larsen, a retired biology teacher. All BLT did was to reflect the fashionable beliefs of their audience, which worked all the time their audience believed.