Is the saying: "O servants of God, what is this calamity?" considered polytheism (shirk) or disbelief (kufr), if uttered in a moment of anger without the intention of seeking help from other than God, and it is a common expression?

If by this phrase one does not intend polytheistic seeking of aid, then it is not considered shirk (polytheism). However, if one intends seeking aid and assistance from a created being in matters that a created being ordinarily cannot do, then it is shirk.