I had dinner at Chipotle Mexican Grill (NYSE:CMG) last night, something that is probably true of a lot of fans of fast casual dining. However, my experience was a bit unusual -- at least compared to the dozens of other times that I needed to scratch my carnitas bowl itch over the past decade.

Here's a snapshot of the Chipotle I went to in Miami last night. It was 5:20 p.m. See if you can spot anything unusual.

 

Image source: Author's photo.

Disregard the seemingly satisfied patrons or even the low-lying overhead lights that seem to cover the menu boards from my vantage point sitting in the middle of the dining room. If you're wondering why there are just two employees on the assembly line, it's because the others are tidying up behind me. If you're wondering why Chipotle hires are cleaning up the place or refilling fixings instead of assembling tasty burritos, it's because there isn't a single person in line.

Sure, one can argue that 5:20 p.m. is a bit early for the dinnertime crowd, but I can assure you that I have often found myself at this same Chipotle at roughly the same time with a line that's at least 20-deep in hungry customers.

Obviously this isn't the same scenario that played out across the country last night. I'm sure most of the taco titan's 1,931 locations were buzzing last night. However, if comps ultimately prove mortal by the time that the market darling reports fourth-quarter results early next year, it will prove that I wasn't just seeing things in an odd fluke of an experience last night.

I'm not turning my back on Chipotle. Even with the stock opening this morning 23% lower than where it was at it summertime peak, it remains one of the best recommendations that I've ever made for David Gardner's Motley Fool Rule Breakers newsletter service. The stock is up 863% since I initially singled it out for newsletter subscribers eight years ago. However, I am concerned that most bulls are merely dismissing the recent E. coli outbreak as a way to lock up a classic growth stock at a discount -- without considering that there may be real ramifications to last month's incident where the burrito roller had to temporarily close 43 restaurants in the northwest after several customers became ill. 

It's also not an isolated event. The cult fave with the "food with integrity" banner has had other unfortunate incidents lately. From dozens of customers and employees getting sick with norovirus-like gastrointestinal symptoms at a single location in California over the summer to the carnitas shortage that limited menu offerings earlier this year, it's not as if we can say that 2015 had been a model year for the burrito baron. 

The chain is feeling pretty mortal these days. The same quick-service operator that was feasting on double-digit comps growth for more than a year since early last year is now experiencing decelerating growth at the store level. Most eateries would've loved to post the 2.6% year-over-year uptick in comps that Chipotle delivered in its latest quarter, but that's pretty light by the chain's historical standards.

Chipotle has a lot of great things going for it. You don't have too many concepts that eat their own cooking with nearly 2,000 company-owned restaurants. The lucrative model where the initial investment to build out a new location is made back in less than two years is the stuff of legend. However, I can't be the only one that will be holding my breath as Chipotle gears up to report fresh financials for the current quarter. I love short lines as a customer, but investors aren't going to see it that way if it becomes a regular occurrence.   

Rick Munarriz has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Chipotle Mexican Grill. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.