With this basic overview of the scheme of the Act in mind,
I turn to a consideration of the two issues raised on this motion.
Discoverability in Relation to Claims for Contribution and
 The Hart defendants argue that claims for contribution
and indemnity are subject to an absolute two-year limitation
period commencing on the date of delivery of a claim against the
first alleged wrongdoer. They argue that this is the result of the
combined operation of ss. 18 and 5(2) of the Act, which in their
view excludes the application of the principle of discoverability to
claims for contribution and indemnity. They maintain that the
limitation period in respect of the claims for contribution in this
litigation began running on May 9, 2011, the date of the service of
the statement of claim in the main action. Because the claims for
contribution were not commenced until November 2015, approximately four and a half years later, they were not commenced in
a timely manner and should be dismissed.
 The Hart defendants rely in particular on the judgment of
Perell J. in Miaskowski (Litigation guardian of) v. Persaud.3 In
Miaskowski, Perell J. was of the view that s. 18 of the Act provides that a claim for contribution and indemnity is “deemed to
be discovered” on the date upon which the “first alleged wrongdoer was served with the claim in respect of which contribution
and indemnity is sought”. Perell J. placed particular emphasis on
the use of the word “deemed” in s. 18 which, he noted [at para.
82], was a “declarative legal concept [that is] a firmer or more
certain assertion of the discovery of a claim than the rebuttable
presumption of discovery contemplated by s. 5 of the Limitations
Act, 2002”. He further observed that s. 18 did not contain
the moderating language “unless the contrary is proved” that is
found in s. 5(2) of the Act. In his view, [at para. 94] “by using the
language of a deeming provision without any reference to the
deeming of discovery of the claim being rebuttable, the legislature
intended to impose an absolute two-year limitation period with
respect to claims for contribution and indemnity”.
 In Perell J.’s view, this approach would bring certainty and
efficiency to the law of limitations, while remaining consistent
with the policy purposes of the Act. He also noted that it would be
a rare case where a defendant would not know whom to sue for
contribution and indemnity, and the period of two years following
3  O.J. No. 1208, 2015 ONSC 1654 (S.C.J.) (“Miaskowski”).