I would not be at all surprised if it returns quickly and often. This time of year is tough for the inexperienced fledglings. I think many die of starvation, or come close, and they will do anything for a meal, even endure physical pain or dangers their parents would never get close to.
It really is a shame you can't have a big, beefy rooster to guard your flock. The small hawks are definitely no match for a big rooster. I once found a dead Coopers or Sharpshin hawk in a pen with only Legbars, I assume the young legbar cockerels ganged up on the little hawk and it could not get away in the enclosed space. In a free-range situation, the hawk would just fly away and probably stay away.
I also have Polish for the first time (Gold Laced) and they are hysterical looking, but I can see how a predator could sneak up on them.