Its probably fine, all 3 of the right-most pins are 12V, and they're all connected in parallel. so the drive will still receive power.
Unless its some crazy 15.000 rpm drive, that actually needs all three pins to split up the current, it should still be well within spec.
As for the little piece of copper, check all the pcb's especially the horizontal ones, like a gpu. And if your power supply is mounted with the fan upwards, I'd take it out and give it an upside down shake just to make sure.