Flagstream should still get lawyers involved
IAAL (but this is not legal advice).
That sounds like a nice idea in theory, but: 1/the mistake has been undone, and 2/damages are likely to be minimal. At this point, getting a lawyer involved is going to be a lot of cost without much benefit.
They look like a pretty small company. The damages they could recoup might not be high enough to justify the costs.
IAAL (but this is not legal advice).
That sounds like a nice idea in theory, but: 1/the mistake has been undone, and 2/damages are likely to be minimal. At this point, getting a lawyer involved is going to be a lot of cost without much benefit.