Ever since the shadow of doubt fell upon his companies, Mr. Adani has kept a relatively low profile within India. He stayed busy abroad. He opened a new port in Haifa, Israel, where he posed with Mr. Modi’s friendly counterpart, Binyamin Netanyahu. And he did tours of Europe and the United States to assure investors that he was standing strong. But Mr. Modi, once ubiquitous by his side, has refused to mention Mr. Adani in public.

The findings from the Supreme Court’s committee suggest that the Adani Group can now relax as far as the Indian authorities are concerned. Without investigative powers that they lack, the regulators are incapable of pursuing the suspicions set in motion by Hindenburg Research in January. India’s political opposition, seizing on the connection between Mr. Adani and Mr. Modi, has been calling for a special parliamentary panel that might unearth more. But between the court and Mr. Modi’s parliamentary majority, they stand little chance.

The Adani Group’s position within India’s political economy looks strengthened, if not fully repaired. That is an important development for more than just the stock market’s winners and losers. Mr. Modi’s vision for India depends on building a great deal of infrastructure.

The country has already sped up and improved a record number of projects during his nine years in power. Airports, highways, power transmission and more are all drastically better and more plentiful, more so than other indicators like private investment, which economists say is lagging. Much of the funding comes from the government. But building needs private partners, too.

Hindenburg Research, which is in New York, had argued that the Adani conglomerate was artificially pumping up its valuations to raise money that it needed to cover its debts to investors abroad. Adani has taken action to pay down its debt load, but it still could attract scrutiny from foreign regulators.

But within India, Adani’s critics may need to alter their plans. Opposition parties complain that they have been prevented from talking about Adani and Mr. Modi in the press and even in Parliament. Adani’s local competitors and partners alike must reckon with the fact that its central place in Indian business remains secure.