Why an unreported signal is not a bad signal
A provider that did not answer has told us nothing, and nothing is not the same as bad. Scoring an unavailable check as zero would punish a token for a provider outage and make two very different situations produce the same number. Unobserved signals leave the weighting, the remainder is renormalised so the score still means out of 100, and the confidence falls to say how much evidence is behind it.