Since apparently unnecessary information is "necessary"...

FC mate and I both had the idea to feed/train our FC's birds. He'd fed all but mine and his, and I went out to do the exact same thing.

I fed mine and his, while he had the window still up. Game did not give him an error that the birds were resting, nor did it give me one, and thus I was able to feed them right after he did.

Time: around midnight Pacific 8 July
Frequency: once
World name: Excalibur
Character name: Nadirah Serenity
NPC name: Chocobo Stables
Monster name: n/a
Class/Level: SMN 59
Party or solo: solo
In-game time: n/a
Area and coordinates: Lavender Beds 2nd ward, plot 3(large)
Steps:
1. Open chocobo stables interface to feed birds
2. Have someone else also feeding birds, but not having fed all of them
3. feed birds they have not
4. have the other person feed the birds you just fed

Birds have been fed twice in a few minutes of each other.

Connection Specs
- Type of internet connection/provider: SuddenLink Communications, N California, USA
- Modem maker/model number: n/a

PC Specs
-=-=-=-=- System Information -=-=-=-=-
Available upon request, however I feel is irrelevant
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Laptop Model Name: n/a
Laptop Model Number: n/a

Gamepad Manufacturer: n/a
Gamepad Model Name: n/a
Gamepad Part Number: n/a

Browser Information
- Name and version of the browser currently in-use: Firefox 39.0
- Internet Explorer Version: people use IE?

Additional information:
Image clearly showing two birds fed twice approximately 4-5 minutes apart. When I opened the window, my bird(Wynter) and his bird(Wyrbelwynd) had not been fed. I fed them. Apparently he'd already fed them.