I have a new name for this - the Sneaky פתח.
When בני ישראל are faced with the ominous situation of having a sea on one side, and an invading Egyptian army on the other, some pretty harsh words are hurled in משה's direction. Among them is the statement, "הֲלֹא זֶה הַדָּבָר אֲשֶׁר דִּבַּרְנוּ אֵלֶיךָ בְמִצְרַיִם לֵאמֹר חֲדַל מִמֶּנּוּ וְנַעַבְדָה אֶת מִצְרָיִם" - this is what we told you in Egypt, "Leave us alone..." Special attention must be given to the word חֲדַל. In its correct form, it is the second-person imperative. However, if it is simply mispronounced חָדַל, it changes to the third-person past tense. A very subtle difference but a very serious change in meaning.