“Sounds in”—I once asked a professor who had just used the phrase what it meant, and he couldn’t come up with a definition using other words. The inability to define a word or phrase isn’t necessarily bad by itself—it could be one of those language-specific concepts that defies rational explication but with whose subtle inflection of meaning every native speaker is intimately familiar. I understand that “X sounds in Y” is a precise shorthand for the rougher concept “the general legal basis for X is Y;” I’m just bothered by the sloppiness of the metaphor. I know how you can sound off, but not how you can sound in. Using “sounds like,” “resonates with,” or “is situated in” would fix the imagery without seriously impairing the meaning.
“Emergent” for “emergency”—I don’t know where this usage comes from but I would hope that it hasn’t been with us long enough to have achieved permanent resident status. Emergency is a perfectly good adjective whose common meaning expresses exactly what you mean when you say emergent. Use it. Your motion is not emergent in the sense that it rises up above the surroundings or that it is in the process of coming into view. Those are the meanings that most listeners will first associate with the word. If, for some unknown reason, you nevertheless feel compelled to use a word ending in -gent, use urgent.
“De minimus” for “de minimis”—Plausible bad Latin is one thing. But mistaken phonetic reconstructions of Latin are something else entirely. The preposition de takes an ablative ending. “-us” is never an ablative form. End of story. Like so many other common disasters of legal Latin, this one can be blamed on lawyers’ sloppy pronunciation. If it weren’t for the lawyers who sloppily said “mi-ni-muss” instead of “mi-ni-meace” (to rhyme with “peace”) or even, if they must, “mi-ni-miss,” we wouldn’t have this problem. Then again, I probably shoudln’t get started on Latin pronunciation, or I’ll be up all night.