People more often say that to save face by implying the issue you identified would be reasonable for the author to miss because it's subtle or tricky or whatever. It's often a proxy for embarrassment

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estimator7292 9 hours ago | parent [-]

When mature, funtional adults say it, the read is "wow, I would have missed that, good job, you did better than me".

Reading embarrassment into that is extremely childish and disrespectful.

	▲	mulmboy 7 hours ago \| parent [-]
		What I'm saying is that a corporate or professional environment can make people communicate in weird ways due to various incentives. Reading into people's communication is an important skill in these kinds of environments, and looking superficially at their words can be misleading.