Legally, no. The legal question of intent is exactly the question of what was going on in the mind of the person allegedly committing the crime.
We as a society definitely judge peoples intent without knowledge into peoples mind, assumptions are made ( correctly or incorrectly ).
I even looked up Australia's definition to make sure it was the same as everyone else's: https://www.ag.gov.au/crime/publications/commonwealth-crimin...
(it's the same)
The only reason I used "very little" is because it is possible for an observer to witness the subject yelling "I intend to kill you!!!!" at the top of their lungs and in that case the observer could be useful at establishing intent.
Legally, no. The legal question of intent is exactly the question of what was going on in the mind of the person allegedly committing the crime.