I agree with David_Gerard: when I say I'm doing something, it appears to the reader as though I'm doing that thing.

I would also agree with various more-strongly-worded equivalents, such as "when I say I'm doing X in a series of acts that includes Y, it's disingenuous to later claim that Y wasn't intended to do X."

Hence, understatement. That is, an expression worded less strongly than, in my opinion, the situation justifies.