Anything under a cheeky dollar this is a steal, page-26

It's an important question about consent and it's something the St V's HREC would have looked at closely before approving the project.

Other brain injury research that trials interventions in ED where patients may not be conscious at screening have relied on the deferred consent process in the NHMRC National Statement on Ethical Conduct in Human Research from 2007.

https://www.nhmrc.gov.au/about-us/publications/national-statement-ethical-conduct-human-research-2007-updated-2018

Section 4.4 of the statement sets out a stepped process for deferral of consent in certain circumstances where patients are medically dependent and can't give consent to participate in research so I'm guessing that the ethics application would have covered this, given that a small percentage of people may not be conscious at screening. As others have said, in most cases the patient themselves or next of kin could be around to give consent if they want in.

The team have got most things right so it's probably safe to assume they were all over this one