Er, yes they do!
This is what the guidelines say: [For breaking news [...] outlets are serviced according to a list of priorities. For domestic news, the correspondent first records a summary - a “generic minute” - for use by all outlets and then priority is given firstly to Radio 5 Live, then BBC News and decisions thereafter are taken according to which programmes are on air.]
Like I said, Radio 5 Live is the priority over the TV channel.
It's a pity you feel the need to sidetrack this thread with such triviality.
However, for the sake of completeness, you claim that not mentioning this incident on the BBC News Channel until after 12 noon, and not providing any meaningful analysis until after 6pm, while at the same time have rolling US election coverage that repeats every hour (the same circa. 10 minute report was being repeated every hour) is in accordance with the guidelines.
First, the prioritisation guidelines you quote (and it would be helpful to provide a
link) apply "where only a single correspondent is available". Even if all BBC correspondents bar one
had flocked to the US, it is not correct to interpret the guidelines as stating that Radio 5 Live should cover the story and the BBC News channel can wait until 'whenever'. The guidelines state that the "only available correspondent", after having covered the story for Radio 5 Live, should
then cover the story for the BBC News Channel. You state yourself (post #241) that this incident was not only being reported by Radio 5 Live, but also by BBC Radio London, and that "there was a live update page from [the] BBC London [website] from 7am". The guidelines are therefore not in point.
In future it would be good if you could properly read the materials you quote and not try to generate futile arguments.