<p>Original:
After a 1991 attempt to overthrow Mikhail Gorbechav failed, the power had shifted to Russian president Boris Yeltsin.</p>
<p>Correct:
After a 1991 attempt to overthrow Mikhail Gorbechav failed, the power (shifted) to Russian president Boris Yeltsin.</p>
<p>Why is the original not correct? There's two actions, the attempt failing and the power shifting, so why isn't the power (had shifted) correct?</p>