If a probe has name "FOO", then sr_parse_triggerstring will consider any string which starts with "FOO" to be a match for this probe. So you can type FOOBAR=r or FOO77=f or whatever. This becomes especially troublesome when the probes have names like "0" through "15", because the input string "12" will match probe "1", and not "12" as intended.
Do you have a commandline example?
Well, something like sigrok-cli --driver=ols -t 25=1 would set the trigger on probe 2 instead of 25. (Why do you ask for examples if you decided not to fix the bug?)
I just wanted an example that demonstrates it, this is sort of vague as a bug report otherwise. I'd expected you to reopen when you provided one. So yes, I can see the problem now, reopening.