(iii) A waiver of the right to file a petition under this subheading
prior to the expiration of the 210-day period established in paragraph (3) of this
subsection shall conclude the State postconviction review process for the purposes of
§ 75 of this article.

(iv) The revocation of a waiver under subparagraph (ii)1 of this
paragraph shall continue the State postconviction review process for the purposes of
§ 75 of this article.

(v) The revocation of a waiver under subparagraph (ii)2 of this
paragraph shall continue the State postconviction review process for the purposes of
§ 75 of this article until the filing of a petition for postconviction relief or the
expiration of the 210-day period established in paragraph (3) of this subsection,
whichever occurs first.

(b) For the purposes of this subtitle, an allegation of error shall be deemed to
be finally litigated when an appellate court of the State has rendered a decision on
the merits thereof, either upon direct appeal or upon any consideration of an
application for leave to appeal filed pursuant to § 645-I of this subtitle; or when a
court of original jurisdiction, after a full and fair hearing, has rendered a decision on
the merits thereof upon a petition for a writ of habeas corpus or a writ of error coram
nobis, unless said decision upon the merits of such petition is clearly erroneous.

(c) (1) For the purposes of this subtitle, an allegation of error shall be
deemed to be waived when a petitioner could have made, but intelligently and
knowingly failed to make, such allegation before trial, at trial, on direct appeal
(whether or not the petitioner actually took such an appeal), in an application for
leave to appeal a conviction based on a guilty plea, in any habeas corpus or coram
nobis proceeding actually instituted by said petitioner, in a prior petition under this
subtitle, or in any other proceeding actually instituted by said petitioner, unless the
failure to make such allegation shall be excused because of special circumstances. The
burden of proving the existence of such special circumstances shall be upon the
petitioner.

(2) When an allegation of error could have been made by a petitioner
before trial, at trial, on direct appeal (whether or not said petitioner actually took
such an appeal), in an application for leave to appeal a conviction based on a guilty
plea, in any habeas corpus or coram nobis proceeding actually instituted by said
petitioner, in a prior petition under this subtitle, or in any other proceeding actually
instituted by said petitioner, but was not in fact so made, there shall be a rebuttable
presumption that said petitioner intelligently and knowingly failed to make such
allegation.

(d) For the purposes of this subtitle and notwithstanding any other provision
hereof, no allegation of error shall be deemed to have been finally litigated or waived
where, subsequent to any decision upon the merits thereof or subsequent to any
proceeding in which said allegation otherwise may have been waived, any court
whose decisions are binding upon the lower courts of this State holds that the
Constitution of the United States or of Maryland imposes upon State criminal
proceedings a procedural or substantive standard not theretofore recognized, which