Theory:Doctor Who television discontinuity and plot holes/Kerblam!

From Tardis Wiki, the free Doctor Who reference
You are exploring the Discontinuity Index, a place where any details or rumours about unreleased stories are forbidden.
Please discuss only those whole stories which have already been released, and obey our spoiler policy.

This page is for discussing the ways in which Kerblam! doesn't fit well with other DWU narratives. You can also talk about the plot holes that render its own, internal narrative confusing.

Remember, this is a forum, so civil discussion is encouraged. However, please do not sign your posts. Also, keep all posts about the same continuity error under the same bullet point. You can add a new point by typing:

* This is point one.
::This is a counter-argument to point one.
:::This is a counter-argument to the counter-argument above
* This is point two.
::Explanation of point two.
::Further discussion and query of point two.

... and so on. 
  • Runaway Bride established that entering the TARDIS is impossible unless connected to the TARDIS (like those particles in Donna) or the Doctor materialises around the object (as showcased in The Parting of the Ways,). So how does the 'Kerblam!' postman teleport aboard?
A junk mail robot does it in The Greatest Show in the Galaxy. Runway bride broke continuity, not this. And perhaps the shields were up.
That doesn't really explain how though? And Runaway Bride justified it as she had pariticles in her connecting them.
Maybe after the Doctor recognised it as a teleport pulse, remembered she ordered something and temporally let the shields down to allow the Kerb!am Man to teleport in.
The TARDIS let her shields down herself perhaps? The TARDIS knew it was someone asking for help rather than a treat.