Looking at both exams, isn't the difference in the way the GST is recorded purely based on the units we are accounting for. In the 2008 exam only 15 units of the 20 were delivered, yet in the 2009 exam question referred to the entire delivery. But in any instance the total GST on the sale is recorded.
In the first image, the GST is 10% of the Sales column of 5500 because the question asked about after all the deliveries were made. The second image shows 250 GST which is the total GST charged, yet only 2300 of the sales revenue is recorded in the SJ since the other 200 is in the GJ as credit to sales revenue.
I may be entirely off track here, but hope that somewhat helps...if it makes sense.

I had immense trouble with this in this years SAC, but I figured out how to do it today and that's how I understand the difference in this particular scenario.
EDIT: Oh I think I see what you're talking about. I don't think I associate the GST with the deposit the way I do it. It's pretty complicated though, I have no idea how they would treat it in a real life scenario.