You handled the Webb authority cleanly and framed the issue well. The 1994 Act application was the missed mark — the examiner report for this paper specifically flagged that candidates citing the Act without sections lost the merit band.
Right now you say "the Act codifies the position" but never reach for the specific provision.
You name Finlay CJ and the doctrinal hook (res nullius) but stop short of the actual ratio line.
Side-by-side on the two paragraphs the examiner report calls out as differentiators.
"The Act of 1994 codifies the position by vesting all archaeological objects in the State. This appears to remove the common-law uncertainty Finlay CJ resolved in Webb."
"Section 2(1) of the National Monuments (Amendment) Act 1994 statutorily vests in the State the ownership of every archaeological object found in the State... thereby giving legislative force to what Finlay CJ characterised as the State's sovereign claim over res nullius."