You're completely missing the point. The analyst is not basing anything on no change. He clearly states it's an academic exercise, a thought experiment. He is not saying oil prices will remain this low forever.
It's just a metric to measure the debt load vs leverage to the oil price of various oilers on the ASX. What it is really saying is that Santos has taken on a large debt load for fairly marginal projects, so it is most vulnerable to oil prices. Which anybody familiar with GLNG would fully agree with.
It's just a tool to quantify that vulnerability. It's only an estimate anyway because full details of the debt, the terms of the JVs and the performance of the assets are unknown.
The second part of the thought experiment is to compare these calculations with where the SPs of these companies are, and he points out that all SPs are well above it, not just for STO but others too. The inference is that the market doesn't believe oil will remain this low for long either.
