DON'T pull the tube. Yes, there might be a cuff leak or some other equipment malfunction, but I would take a look down with the laryngoscope to see exactly where my tube was. You can always reconfirm, or pull and reintubate. At least with the tube still in there, you have some sort of landmark (i.e. esophagus or trachea). This can be a sticky situation if your partner is "SURE" the tube is in the trachea (happened to me, tube was in the belly). Be sure to repeat all of your confirmatory steps if you ever think that the tube may have moved. What were lung sounds like? ALWAYS recheck when the pt is moved as well...
Other than that, I don't know...