How can a buyer verify hit likelihood in a repack break?

Ask whether the hit rates were locked before the break and timestamped. BreakersDNA calculates hit likelihood from a certified manifest and locks it before the first pack opens, so the figure on screen provably did not change once cards started appearing.

A likelihood figure that can be revised after the fact proves nothing. Locking and timestamping matters as much for the honest breaker as for the buyer: it means the numbers shown on stream cannot be second-guessed afterwards, because the record proves they were the same before and after the pull.