The last thing you want to do is to give excuses for poor performance, no matter what it is. Adcoms will see right through this. There are ways that you can incorporate your experiences and how maybe there were some extremely difficult circumstances that may have pinched your focus during a period of study in school, etc, but never give any excuses like: the reason I got a bad MCAT score was because of this, or I got really sick. Although it very well may have been really tough for you, many will not see things the way you do. I would not even bring it up in an interview, unless the interviewers specifically asked it of you, or you some how tied it into an answer to another question.
The bottom line is that many many students get looked at with bad MCAT scores. If you get an interview with a bad MCAT score, then it would be pointless to bring it up again.
Good luck to you.