There are plenty of well documented and unambiguous cases where the CIA has overthrown governments, directly interfered in elections and exerted covert influence but Ukraine really doesn't look like one of them. Possibly in the covert influence sense, sure, but nowhere near at the level of determining the outcome.

The constitutional crisis in Ukraine in 2014 was between President Yanukovych and the Ukrainian Parliament, which is actually the sovereign institution. In a constitutional sense it wasn't even really a revolution because the sovereign institution was never overthrown. It pressured Yanukovych into resigning, backed by massive public support.