For one, you don't need to be a dick.

For two, he seems to be talking about brewing with extract - probably the Coopers hopped LME cans that abound in Australia. For those, a general accepted practice is to simply mix the LME with pre-boiled water in your fermenter. However, not everyone is happy with straight Cooper's beer, so they will make a hop tea for bitterness.

So he seems to be suggesting that the best way to utilize your hops for this hop tea is by making a 1.040 gravity wort and boiling it with at least 10L of wort.

When he says you get 85% out, he probably means you're getting 85% of the maximum possible hop utilization.

None of this sounds unreasonable to me. We know the online calculators are wrong because they assume a more or less limitless increase in IBUs from water volume and boil length. OBVIOUSLY, that can't be the case. Like anything in chemistry, there are diminishing returns with concentration gradients.

So we'll chalk your misunderstanding of what he meant by using a 1.040 gravity wort for hop utilization, that's understandable if you don't know how the Aussies do their extract batches. That brings us to volume. Do you have any evidence to suggest that using >10L is going to extract significantly more AA than using 10L, given a typical amount of hops for a typical-sized batch?