Measuring higher current than rated limit is forgivable, measuring voltage in current mode is unforgivable.
Gulp! Guilty as charged
The beeping/warning function on my fluke 87 has saved me more times than it should.
Crawling around control cabinets, climbing around getting to field devices and measuring a bunch of different stuff whilst fault finding some intermittent, convoluted system, sometimes you just forget.
In the "bad" old days when working on live panels was the norm, just the sight of those huge, discoloured bus bars would give me the heebie-jeebies, so naturally you try and pick equipment that would instil some confidence