Mustang V6 4.0 broken valve spring?

I just bought a 2010 V6 mustang (4.0). After a week of using, I had a breakdown on Friday.

I had the engine light blinking and the engine was knocking.

I stopped as soon as possible. I tried to crank it up several times and in the beginning it was doing so and keeping the idle even with the misfire.

But then it stopped running and was not even able to hold the idle.

I got it towed to Firestone and after 3 days of investigation they found out that a valve spring was broken on cylinder 6. They have to send it to Ford to get it repaired.

My question is: Does it have necessarily caused other damages? (head, cylinder, piston…)

Prob not, but never use Firestone, etc, again.

use the brand name dealer, Ford, when at all poss.

Probably. If the valve spring broke the valve fell partially down into the cylinder where it got hit thousands of times by the piston.

In support of "Minister of Truth" thumbs,
likely no collateral damage because,
because for one, it's a non-interference type engine. Typically valve just sits there. If a result of being over revved, possible valve may have been kicked by the cam. But it likely would have been hit only once by the piston if anything. Pushed back and face is likely bent. But that should be it. Valve dropped, they'd hear it and tell ya. Typically the valve seal and keeper will hold it enough to keep the valve from dropping even if the keeper was toast seal (serviceable condition in first place) is purdy tight.
prolly spring, keeper, seal, valve replacement (for GP's or not). Valve grind/lap. Inspect cam lob. Done.

seasoned machecnic would tell ya if you "dropped" a valve during the proccess.
typically one can hear a valve if it was bouncing around in a chamber. And the plug electrode would likely show damage as it would likely be beaten by the valve or the part that broke off after being hit.