Sorry, it’s a year or so since it last happened (I haven’t been interacting with projects with heavy templates so recently) and I can’t remember any of them off the top of my head. One that I recall (but not the project or word) was a fairly common English word with two senses where I would have expected one or two false positives only, another was something more along the lines of “Versions (`uname -a`, `mylangc --version`, `mylangpkg --version`):” making “mylangpkg” unsearchable (in cases like this, disciplined use of labels can mitigate the damage).
The problem is that as soon as the template contains the word you’re searching for, every issue matches your search.