A bit of a counterpoint but I actually had an opposite experience with a wedding-planner-zilla. We got married at this fantastic venue in the Texas hill country and they provided us with a "day-of" coordinator who was only supposed to be there to work with the vendors while we're getting dressed and, you know, married...
After one meeting and a couple phone conversations with this person we realized she was going to be very little help, so we made sure our vendors knew everything we wanted and even sent schedule updates the morning of the event. I don't know what her problem was, and it may have just been incompetence and not bad intentions, but she proceeded to rain sabotage down on our wedding day.
The last thing I do, after getting dressed and ready but before going to the altar, is go meet with the caterers and bartenders who have just arrived to make sure everything has been communicated. Then I go down to the ceremony and wait at the altar. Thirty minutes later the wedding path finally starts entering. The Best Man and Maid of Honor enter last.
Then nothing. For another thirty minutes. I'm understandably a little concerned at this point. The musician is confused and I'm not sure what his signal was supposed to be but "here comes the bride" plays three times and no bride. Finally she enters and everything goes perfectly. Ceremony ends, pictures start.
Coordinator lady leads guests to cocktails while family stays for photos. Family leaves while I take more pictures with my beautiful new wife, strutting around on cloud 9. We talk a little and I found out all the delays were just because the wedding planner "thought we needed to wait" and "couldn't find the bride." She 'couldn't find the bride' because the wedding coordinator TOLD her to wait off at some distant point and then just left her there.
Then the coordinator finds us and she informs us that dinner is being served without us because she basically told all the vendors to disregard our schedule and instructions because "it wasn't going work anymore."
I spoke to the caterer, this conversation happened while my wife was standing there with her father waiting to start the ceremony.
So we are forced to rearrange our reception, since we were planning to enter and do our first dance before dinner. Not the biggest deal to me, but upsetting since my wife spent an unreasonable amount of time planning every detail.
What really stood out was that the coordinator was being such a bitch while delivering the news, and rudely refusing to answer questions or discuss anything, that not only my wife was crying but our photographer had broken into tears she felt so bad for us. On our wedding day she made my wife cry and told her to shut up a couple times.
I was not pleased.
Overall the wedding was fantastic and the ceremony was beautiful once it actually happened, the reception was the party of the decade and upon reflection the turbulence she caused wasn't even noticed by most of our guests. But I will never forget that bitch that darkened the brightest day of my life, and I will never know if she did so out of malice, incompetence, or just because she was too apathetic to listen to a word we had said to her.