An rawaito wasu sakwanni dake cewa ofishin jakadanci Amurka dake Najeriya ya bayyana irin yadda aka shiga cikin wani yanayi na rudani game da ko wanene ke jan ragamar mulki a Najeriyar lokacin da marigayi shugaba Umaru Musa Yar'adua ke fama da rashin lafiya.
