That is not the issue. The issue is compatibility.
Any instructor certified to teach will be able to teach you scuba.
The issue is that you as a student may not like the instructor's personality or style. The best way to ascertain that is to speak with him/her. You will quickly be able to tell if the instructor seems impatient, uninterested, flippant, arrogant, inflexible, in too much of a hurry, disrespectful, or any of a number of individual qualities that may be incompatible with your own personality. You can also tell by the instructor's choice of words whether she/he is of the same social background and education as you are.
If you can get a chance to watch the instructor teach at a pool, that would be even better, but not necessary as critical as just a friendly discussion, about gear choices, or simple things like that.