Yes, plural. Eight "Coke bottles" appear during Buzz Aldrin's mobility experiment and appear onscreen from a fraction of a second to about six seconds. We now know that they are actually flares inside the TV camera, which is confirmed by them crossing "in front" of Buzz instead of behind him, and by them not appearing in the 16mm DAC footage.

JayUtah provides a full analysis on his web site:
http://www.clavius.org/cokebottle.html
http://www.clavius.org/bibcoke.html

Here's when and where to view the flares in the Spacecraft Films' Apollo 11 DVD No. 2 -- EVA Part 1, chapter 7. The times and dialogue may help to locate them in other copies of the TV transmission, between the flag raising and President Nixon's phone call.

Time and location on screen:
1. 53:24-28 Lower left to right, starting below LM footpad.
2. 53:35-36 Top right just above the horizon, extending out from Buzz's visor next to the flag.
3. 53:44 Briefly as Buzz passes the flag, just right of and below centre, moving towards the base of the flagpole.
4. 54:11-12 Bottom left to right.
5. 54:51-57 Bottom left to right.
6. 55:01 Very brief, bottom right of picture.
7. 55:02 Very brief, bottom right but a little higher.
8. 55:03 Very brief and higher still, over Buzz's PLSS.

Dialogue with times in bold:
GET 110:13:15 Aldrin: 52:36 I'd like to evaluate the various paces that a person can (garbled) traveling on the lunar surface. I believe I'm out of your field of view. Is that right, now, Houston?

GET 110:13:30 McCandless: 52:49 That's affirmative, Buzz. (Pause) 52:58 You're in our field of view now.

GET 110:13:40 Aldrin: 53:00 You do have to be…[listens to McCandless]

GET 110:13:42 Aldrin: 53:02 Alright. You do have to be rather careful to keep track of where your center of mass is. Sometimes, it takes about two or three paces to make sure you've got your feet underneath you. (Pause)
No. 1 - 53:24 About two to three or maybe four easy paces can bring you to a fairly smooth stop.
No. 2 - 53:35 (Pause) (Garbled) change directions, like a football player, you just have to
No. 3 - 53:44 put a foot out to the side and cut a little bit. (Pause) 53:59 The so-called kangaroo hop does work, but it seems as though your forward mobility is not quite as good as it is in the conventional, the more conventional
No. 4 - 54:11 one foot after another. (Pause) As far as saying what a sustained pace might be, I think that one that I'm using now would get rather tiring after several hundred (garbled). But this may be a function of this suit, as well as
No. 5 - 54:51 the lack of gravity forces. (Pause)
No. 6 - 55:01
No. 7 - 55:02
No. 8 - 55:03

Pages 319 and 320 of Bennett and Percy's "Dark Moon" reports Una Ronald's story as follows (in part):

"Having decided to stay up and watch what she believed to be live images of the 'Apollo 11' EVA direct from the Moon, she was more than astonished to see a Coca Cola bottle roll across the lower right quadrant of the TV screen! The incident lasted only two or three seconds at the very most.

..."'The TV picture I was watching was extremely fuzzy, you could just about distinguish the movements of the astronauts, but when the Coke bottle rolled across the screen it was totally visible, in complete contrast to the fuzz, it was as sharp as anything. Everyone knows the distinctive shape of a Coke bottle -- the design was *completely* clear.'"

"...you might well think this incident was a trick of the light, or the tired imagination of a wife and mother at the end of a long winter's day down under...

"...she went on, 'but about a week to ten days later, I saw that several letters mentioning this Coca Cola incident were published in the West Australian Newspaper...'"

Note that "Dark Moon" states that she was watching "what she believed to be live images" and that she "decided to stay up and watch... at the end of a long winter's day", whereas this incident would have occurred at roughly noon in Western Australia.

Proof of the hoax! In the 60's and 70's, Coca-cola was sold in 16 oz glass bottles (the tall ones with the thin necks). You could buy them 8 to a pack, in little cardboard carriers.

8 bottles on the moon. 8 bottles in a pack. Coincidence???? I think not..... Insanity???? well, maybe......