Chat Surveys with No Agent

Content

Hello,

I have an odd situation occurring on one of my chat surveys.  Viewing survey results, I occasionally get instances with "No Value" in chats.acct_id.  These almost always have very low scores, and end-user entries along the lines of "I was never connected to an agent".  When I attempt to view the records, there is no Incident record, and the Chat record is always some variation of: 

Time             Chat Event

[time stamp] Chat Created

[time stamp] Chat Canceled

[time stamp] End-User Disconnected

So, it appears that sometimes end-users with abandoned/cancelled chats are being offered surveys.  I cannot replicate this experience when I test.  Should this be possible?  And, is there anything I can do to prevent it?