Will one with record of unfinished PhD on his/her CV be doubted of his/her ability?
does a record of an unfinished PhD program makes employers doubt a person's ability?


I very much wish it were not so, but the honest answer is yes. Employers, within the restricted context of reviewing job applications, are forced to rely on very partial and superficial information given to them in CVs and job applications. Moreover, they are given huge numbers of applications to select from under time pressure. They respond to this in a way that I think is completely rational, but nonetheless extremely frustrating (to them as well as to the candidates), which is to assign a highly inflated significance to each piece of information given to them: positive things appear much more positive than they should, and negative things appear much more negative than they should. 

In particular, both an unfinished PhD and a long period of seeming inactivity in one's CV are likely to be perceived at least somewhat negatively, certainly if they are unaccompanied by an explanation, and possibly (to a smaller extent) even when an explanation is provided. It wouldn't kill someone's chances of getting a job, and can be overcome by many other positive things one has to say about themselves, but I'm pretty sure it will have at least a small negative effect.