To reproduce:
1. Click on the "root";
2. Push SHIFT + DOWN 2 times;
3. Push CTRL + DOWN 2 times;
4. Repeat step 2;
5. Push SHIFT + UP 2 times;
You will have root and items0-4 selected and focus will be on the item-3;
Then push "Show selection"

You will see that selection model thinks that item-4 is not selected. But it is rendered as selected.