Why "laying low" is a linguistic slip-up

What kind of error is it?

It's a grammatical error involving the misuse of "lay" and "lie".

Why do people make this mistake?

The verbs "lay" and "lie" are often confused because they have similar meanings and because "lay" is both the past tense of "lie" and the base form of another verb. Additionally, in casual speech, incorrect usage has become common, further contributing to the confusion.

What is correct?

The correct phrase is "lying low" because "lie" is the verb that means to recline or be in a flat position, whereas "lay" requires a direct object and means to place something down.