Risks in 1 tick offset + greening up

[traderjo]

After seeing the famous " Win whatever the outcome" video
It sounded too good to be true hence my question
- What is the max risk? I mean after the first bet being matched WHAT IF the automatic second bet NEVER gets matched? The video does not mention much about risk! can one have a stop loss?
- What if greening up never happens?
- Is it possible to automate greening up?

- What is the significance of reversing the field?

- What kind of races does such 1 tick offset + greening up works?
Anybody using it on Australian races?