Discretionary considerations
36 Expo-Net submits that the Nielsen Affidavit provides a fulsome disclosure of all relevant matters relating to the circumstances which gave rise to Expo-Net's application to amend the two patents in suit. Privilege has been waived over various communications as part of that disclosure. The Nielsen Affidavit also explains how it was not until after these proceedings had commenced that the principal error came to light, upon which Expo-Net proceeded expeditiously to file the motion.
37 Expo-Net submits that, in the present case, there are no circumstances which have arisen which would lead the Court to exercise its discretion to refuse to allow the amendments sought.
38 A summary of Mr Nielsen's evidence is set out below.
Mr Nielsen's evidence
39 In 2004, Mr Nielsen, a European patent attorney, commenced representing Expo-Net in respect of its patent matters. Mr Nielsen was (and remains) a partner of the firm Budde Schou A/S in Denmark.
40 On 13 August 2004, Expo-Net (by its then managing director Mr John Klinkby) invited Mr Nielsen to attend Expo-Net's production plant in Hjorring, Denmark. On 20 August 2004, Mr Nielsen visited the plant and inspected equipment which Expo-Net had developed, and was testing, for manufacturing contact filter blocks with rough-textured elements.
41 On 22 December 2004, Mr Nielsen received instructions from Mr Klinkby to prepare a patent specification for the invention.
42 On 12 January 2005, Mr Nielsen sent to Mr Klinkby a "claim proposal" for his approval. The claim proposal was drafted in English, but the covering letter sent to Mr Klinkby was in Danish. The claim proposal referred at Claim 1 (method claim) and Claim 11 (apparatus claim) to the reservoir as having a 'first inlet and a second inlet'. At the time Mr Nielsen prepared the claim proposal he was aware that the reservoir did not have a 'second inlet'. He was also aware that it had a 'first outlet' so that material could be transferred from the reservoir to the heating and pressurising unit. Despite this awareness, the claim proposal contained an error of drafting in that it referred to the reservoir as having a 'first inlet and a second inlet', yet correctly (at line 7 of claim 1) referred to the heating and pressurising unit as having a 'second inlet in communication with said first outlet'.
43 Mr Klinkby then confirmed that the claim proposal met with his approval. He apparently did not identify to Mr Nielsen the drafting error in respect of the reservoir. Mr Nielsen then requested a Mr Jacob Mikkelsen, an experienced trainee patent attorney, to prepare a draft patent specification for Expo-Net's invention. On 8 February 2005, Mr Nielsen reviewed the draft specification prepared by Mr Mikkelsen but did not identify the drafting error (which had been repeated in the draft specification). That same day the document was forwarded to Mr Klinkby for his approval.
44 On 22 March 2005, Mr Klinkby instructed Mr Nielsen to file the draft specification as a European patent specification (European Application). On 25 January 2006, Mr Nielsen received instructions from Mr Klinkby to file a PCT application claiming priority from the European Application (PCT Application).
45 On 3 October 2006, Mr Nielsen received instructions from Mr Klinkby to enter the national phase from the PCT Application in, amongst other countries, Australia and New Zealand. Mr Nielsen then instructed Mr Peter Franke of Watermark Patent & Trade Mark Attorneys (WPTA) to file the Australian and New Zealand national phase applications based on the PCT Application. In doing so, he instructed WPTA simply to attend to filing the PCT Application in the form it was provided to them by him.
46 On 30 October 2006, WPTA informed Mr Nielsen that the PCT Application had been filed in Australia and was known as Australian Standard Patent Application No. 2006226731. The prosecution of the Standard Patent then proceeded in the coming months and years, including receipt of and responding to an Examiner's Report. That Report did not raise any issue which might identify the drafting error in respect of the reservoir.
47 On 24 April 2007, a divisional innovation patent application was filed based on the Standard Patent. That specification was prepared by WPTA and was based on the Standard Patent. An Examiner's Report issued on 22 May 2007 with respect to the Innovation Patent did not raise any issue which might identify the drafting error in respect of the reservoir.
48 During the prosecution of both patent applications in Australia, Mr Nielsen reviewed the specifications but did not identify the drafting error in respect of the reservoir.
49 Specifications for Expo-Net's invention were also filed in New Zealand, Eurasia, Europe and Germany. None of the prosecutions in respect of those specifications drew to Mr Nielsen's attention the drafting error in respect of the reservoir, or provided an occasion by which he became aware of the drafting error.
50 The present proceedings were commenced on 14 May 2009. The respondents filed their Defence and Cross-Claim, as well as Particulars of Invalidity, on 11 August 2009.
51 On 10 September 2009, the respondents were ordered (by consent) to inform Expo-Net which features of the patent claims were said not to be taken by the respondents' method and apparatus.
52 On 25 September 2009, the respondents replied and informed Expo-Net that one of the reasons for non-infringement of the patent claims in suit was that the respondents' apparatus did not have a reservoir with a 'second inlet'. It was this correspondence which drew Expo-Net's attention to the drafting error in respect of the reservoir.
53 Mr Nielsen has searched his files and cannot provide any reference to how or where the drafting error occurred, save that it appeared in the initial claim proposal which he prepared in late December 2004. He is unable to explain why he did not identify the drafting error during his infringement analysis conducted prior to the commencement of the proceedings, except to say that he had always understood that the reservoir had a first inlet and a first outlet, and not a second inlet.