Chipotle tanked after saying it dropped the ball on customer service (CMG)

Chipotle shares slid 7% on Tuesday after the company said it was nervous about hitting its guidance for the year. 
The burrito chain was presenting at a Barclays retail conference in New York.
Its same-store sales have fallen for three straight quarters in the wake of two E. coli outbreaks last year that affected its restaurants in 14 states. 
Co-CEO Steve Ells said inadequate customer service may be lengthening the sales recovery. 
Bloomberg reporter Shelly Banjo t