Nipro Diagnostics Inc.’s acquisition by China-based Sinocare Group was headed to the finish line when it suddenly looked like the deal could be upended.

At 8 p.m. Eastern time on Jan. 7, four hours before the scheduled closing, “we caught word the Chinese stock exchange was experiencing a steep selloff and trading was halted,” said Greenberg Traurig corporate and securities shareholder Matthew Miller. “We were nervous for the next four or five hours.”