"Whether the Congress manages to form a government by supporting JD(S) or not, they shouldn't be criticised for trying. The BJP would be doing exactly the same thing if the positions were reversed," Omar tweeted shortly after the Congress offered support to the JDS.
"What about the other states where BJP sneaked in through the back door? What's sauce for the goose must be sauce for the gander...," he said in another tweet when a television anchor called the Congress move "pathetic" and said "sneaking in from the background would be a negation of the mandate".
Omar quoted former German statesman Otto von Bismarck - "Politics is the art of the possible, the attainable - the art of the next best" when another anchor suggested the mandate was not for the Congress and the JDS.
"By that logic, ALL post poll alliances are wrong & opportunistic," he said.
Unlike Omar, chief minister Mehbooba Mufti was among the first to congratulate the BJP when it looked certain that the party would emerge as the single largest in the southern state.
"Hearty congratulations to BJP for their stellar performance in Karnataka," Mehbooba said in a tweet, although there is no love lost between her Peoples Democratic Party and the BJP, its ally in Jammu and Kashmir.
PDP sources said the party's rank and file would have been happier if the BJP had lost. "This is rather the sentiment across the board in the Valley," a PDP leader said.
Omar had earlier invoked Shakespeare to express his surprise over the Congress's show.
"Et tuKarnataka," he tweeted, modifying a quote from Julius Caesar.
Caesar had uttered the Latin words "Et tu, Brute" when his best friend Brutus had stabbed him.