sales weaknesses

Do you have a salesperson like Bob?

Bob was very anxious over what to write to a suspect that blew him off.  The prospect canceled an appointment and was vague about whether or not he would reschedule.  This stopped Bob in his tracks and he literally spent an entire day getting feedback on what his email should say.  Not only is Bob wasting time, it is time that could be spent finding and identifying additional opportunities, moving existing opportunities along and connecting with customers or clients and collecting referrals.  So what causes Bob to do this and could we have predicted this behavior?