I've had that happen more times than I care to remember, the bigger the fish, the more it pains me.
Although I always find some
one thing to blame it on while I'm out there, many things could have caused it to happen.
My "Short" list of excuses in no particular order:
1. Small group of fish out front, I hook up...commotion scares the rest off to a distant hump.
2. There's a very smart school of fish out there, I happened to catch the dumb one that night.
3. The one fish I released went back to the group and told them it was made of wood. They proceed to ignore any other artificial offerings.
4. I just don't have what they want tonight.,, I should have brought bait/eels.
5. That must have been the only fish within my entire casting radius. (In which case, I am that good that I was able to catch it

)
6. I arrived late, they were staged earlier in the tide...and I just caught the last hurrah of it.
7. I forgot the action that I used in catching the first fish...although I try like hell to repeat it, I know I'm just not doing it the same way.
8. I caught the "leader" of the pack. Upon releasing her, still feeling the soreness in the jaw...she swam for deeper water and the others trailed behind her.
9. It never happens to me if there's a large group of fish because I couldn't suck that bad to only catch one (

)...so this one kind of ties in to #1
10. A loud screaming hum from my line scared them away...,,,

...nah, maybe it was "Happy Hour" at the nearby Eel Grass Pub and the one I caught didn't have his watch on.