Nestec v Dualit - a seriously flawed judgment?

A lot has been written about the recent case of Nestec v Dualit, which seems to have brought the idea of "poisonous priority" to UK patent law in a similar way to the "poisonous divisionals" idea in European patent law. The issue centres around whether an application that claims more broadly than its priority application discloses can be anticipated under Article 54(3) / Section 2(3) if the priority application itself publishes. This concept has been much discussed, and I have written about my own solution to the problem here.

What has not been discussed much, however, is whether the conclusion arrived at by Mr Justice Arnold in the case was actually correct. Having looked in more detail at the judgment, I have come to the conclusion that it is seriously flawed on the priority point.

Claim 1 of the patent, as sought to be amended (by the underlined parts) by Nestec, and as broken down into integers by Arnold J, reads:

[1A] Extraction system comprising a device for the extraction of a capsule and a capsule (16) that can be extracted in the device; 

[1B] the capsule (16) comprising a guide edge in the form of a flange, the device comprising

[1C] - a first fixed part (2),

[1D] - a second part (3) which is moveable relative to the first part, 

[1E] [-] comprising a housing (4) to receive the capsule and defining, in the closed position of the moveable part against the fixed part, a position for extracting the capsule on an axis (25) in said housing, 

[1F] - a part for insertion and positioning comprising guide means (6,7) for the capsule arranged so as to insert the capsule by gravity and position said capsule in an intermediate position; 

[1G] the guiding edge being received in the guide means (6,7); 

[1H] said guide means being insertion slides permitting the engagement of said flange; 

[1I] - a beverage-delivery system (19, 53), 

[1J] said second moveable part (3) being configured to displace the capsule (16) from the intermediate position to the extraction position when the device is closed, characterised in that 

[1K] the guide means (6, 7) comprise stop means (20) configured to retain the capsule (16) in an intermediate position, in a manner which is offset to the axis of the capsule in the extraction position; 

[1L] the flange bearing against said stop means in the intermediate position, and in that 

[1M] the second, moveable part (3) receives the capsule to displace it from the intermediate position to the extraction position on the axis (25) of the capsule in the extraction position in said housing (4) 

[1N] so that, when moved, the moveable part acts on the capsule to move it downwards, 

[1O] the flange of the capsule passing below the stop means (20), 

[1P] and to push it along the axis (25) of said moveable part into its extraction position.

The key part of the judgment relating to the priority question is in paragraphs 95 to 104. In this, Arnold J notes that claim 1 of the patent covers certain arrangements, outlined as: i) the housing receiving the capsule being contained in either the second part (integer 1D) or the fixed first part (integer 1C); and ii) the capsule being offset, inclined or both relative to the extraction axis. Arnold J's view was that, because the priority document did not disclose these different arrangements, which were only found in the later application, claim 1 lacked a valid claim to priority.

On the face of it, this seems to be plausible. However, as any first year trainee will know, there is a huge difference between what a patent claim covers and what it states. The claim in question makes no mention of the housing being in either of the parts [perhaps not: see update below], nor does it require the capsule to be anything other than being offset to the extraction axis. The possibilities of the different ways in which the housing and the capsule could be arranged were therefore only additional possibilities that were added in the later filing. In normal circumstances this would not affect any priority claim at all, as it is perfectly normal practice to add features that might provide further fall back positions in a later priority-claiming filing. Arnold J, however, seems to think otherwise. If correct, this would be extremely worrying as it would result in a substantial proportion of existing patent applications and patents lacking a valid priority claim merely because additional options were added in the later filing, even if claim 1 was left entirely unchanged. Am I missing something, or has Arnold J got it very very wrong?

Update 27 June 2013: To pre-empt any eagle-eyed readers, I have noticed that I may indeed have missed something, although it doesn't affect my conclusion. The addition of the word "comprising" to the start of integer 1E indicates that the housing is part of the second part, not the first part. This would only raise an issue of priority if this could not be unambiguously derived from the priority application, and it was agreed that this arrangement was in fact disclosed in the priority application (see paragraph 96). However, the other point relating to the capsule being possibly also inclined is, I think, still valid.