The thoughts go like this:
1. I want to buy more shares;
2. I want to buy them really cheap;
3. I'll start a rumour that the deal has fallen through;
4. Maybe some other shareholders will believe it enough to get scared and try to sell out quickly;
5. If 4 occurs, SP decreases and my low order gets filled.
6. Happy days.
I think that about sums up SV's thought process.