"This incident has not marred our bilateral ties, but it is a shame that an opportunity for Dichter to share from his experience has gone to waste," Gill said.
Dichter was one of the planners of the assassination of Saleh Shehada, a Hamas commander, in 2002.
Shehada, and 14 Palestianian civilians, were killed by an Israeli air strike.
Doron Almog, an Israeli ex-general involved in the Shehada assassination, narrowly avoided arrested when in London in 2005.
He avoided arrest by returning to Israel after being warned that a British magistrate had ordered his detention.
A federal judge in the US threw out private war crimes proceedings against Dichter in 2005.
Israel has come under international censure for its handling of a Palestinian revolt that erupted in 2000. Israel says its methods are an appropriate response to armed fighters who operate in crowded Palestinian areas and use tactics like suicide bombings.
After Almog's near-arrest, Tzipi Livni, the Israeli foreign minister, asked British judicial authorities to review laws allowing magistrates to issue such arrest warrants.
Livni repeated the request during a visit by David Miliband, the British foreign secretary, last month, Israel's Haaretz newspaper reported.