Pinhead Sized Hole in Down Sleeping Bag

I did an overnight trip on the weekend and used my Mountain Hard Wear Phantom 15 for the first time. Brilliantly comfortable and light, but a bit too warm for this trip. But that's another story. When I was packing it after lunch on Sunday I noticed one or two down "feathers" escaping. On closer inspection I found a very small hole, maybe a pinhead diameter or less through which it was leaking. I unpacked it on returning home, but can no longer find the hole or any evidence of more leakage. So:
1. Can these things self-repair?
2. if I do rediscover the hole, what would be recommended to fix it?
3. Or should I just leave it alone, assuming there is no further leakage?
1. Can these things self-repair?

2. if I do rediscover the hole, what would be recommended to fix it?
3. Or should I just leave it alone, assuming there is no further leakage?