1.
nitpicking; catching someone on slips; fault-finding
the act of finding fault with trivial mistakes in what someone says or does, often ignoring the main point
揚げ足取りはやめてください。
Please stop nitpicking.
Etymology
From sumo and judo: 揚げ足 is the leg an opponent has lifted to attack, and grabbing it to throw the opponent is 揚げ足を取る. Figuratively, seizing on a slip in what someone says.
Usage
Strongly negative connotation. Implies pettiness and missing the larger point in favor of trivial criticisms.