>When a site posts multiple links to a stream, latter ones are “backups” but I’m not forbidden from using them.

That analogy only works if the BOE makes both streams available on a public basis. If the company is contracted only to provide a backup stream in case the primary failed, it stands to reason that they do not have the rights to stream/broadcast during normal circumstances. From a legal standpoint, it would be similar to eavesdropping on the live press conference using a bug.