State of the law at the outset of the action
 The plaintiff has pointed out that in 1999, class action
jurisprudence was only starting to be developed in Ontario and
that Charter jurisprudence was also fairly recent and evolving.
He points out that no Canadian class action brought against the
government on Charter grounds had been finally certified.
 I accept that this was so. However, the evidence falls short
of explaining why this was a cause of delay and if so, to what particular extent. Although reference is made to evolving case law in
2004 and 2010, few if any steps were taken to move the matter
along in a timely fashion following the release of those decisions.
The unavailability of expert evidence
 I accept that expert evidence is required to establish the
link between the use of Mefloquine and the types of events expe-
rienced by Mr. Smith.
 The plaintiff indicates that Dr. Remington Nevin, a scien-
tist at the forefront of research into Mefloquine, has been con-
sulted and is in the process of establishing scientific causation
between the use of the drug and long-term neuropsychiatric
symptoms. The affidavit of Mr. Larmer indicates that Dr. Nevin
was first identified as a potential expert witness in May of 2016.
Mr. Larmer’s affidavit also provides the following, at para. 92:
Over the years, as a lawyer of record for Ronald Smith, I regularly researched
the scientific issues surrounding Mefloquine. Specifically, I would look for any
scientific journal, papers or commentary concerning the use of Mefloquine
causing long term neuropsychotic difficulties, like the ones experienced by
Ronald Smith and others. Unfortunately, I was unable to locate anything
along the lines of Dr. Nevin’s current research.
 It is not clear what specific research was done by Mr.
Larmer over the years. A review of some of the papers contained
in the plaintiff’s supplementary motion record and authored by
Dr. Nevin, and more particularly of the references cited therein,
reveal a good many publications pertaining to Mefloquine and its
neuropsychiatric effects dating back as early as 1996. Even
Dr. Nevin’s papers on the subject date back as early as 2008.
 The evidence is largely silent as to what, if any, inquiries
were made prior to 2016 to locate an expert on the subject.
 I am not, on the evidence before me, satisfied that unavailability of an expert offers an acceptable explanation for the delay.
The plaintiff’s medical condition
 In his affidavit sworn March 31, 2017, Mr. Smith indicates
that throughout the course of this litigation he has experienced