Interesting.
A summary for those not getting the feed. The Defence expert has recorded the sound of a cricket bat hitting the door at various distances. They haven't yet played the comparison with the shots fired at the same distance (unless I missed it).
He determined that it was certain that the cricket bat hit the door after the bullets.
He also determined that Pistorius did kick the door (fibres from his socks left behind).
The lights - if all the lights were off, you could not see the house at all from 70 metres away. No outline - nothing. There was no ambient light hitting it at all.
From that distance, you could see the bathroom light if it were on (it appeared as a suspended light). You could see the toilet window only if the door was open. It was not possible to make out the toilet window if the door was closed. There was no ambient light there either.
He showed pictures of a man standing on his feet beyond the window, and him kneeling. When he was kneeling, you could see the top part (half?) of his head.
This indicates that if Dr Tripp was correct in what he saw, the bathroom light must have been on, and he either saw Reeva cross the bathroom and go into the toilet, or he it was later than he thought, and he saw Pistorius with his legs on, go and try to kick the bathroom door down.
Or he didn't see what he thinks he saw at all.
Inside the bedroom, with all the lights and electrics off, you could see a small amount of light from the bathroom if the lights in there were on - you could see the end of the passage. If not, you could not see. He said that it would be possible to see things when your eyes adjusted to the light, but that would not be immediate.