he played at our school a few years ago how cool is that, except i wasn't interested enough in music to realise how cool this was and thus didn't see it

but you say they were at the con? well i look up the library catalouge for sydney uni and voila they are
Roger Woodward plays Beethoven [videorecording]
Publisher S.l. : Yoho Productions in association with Hocking and Woods Pty. Ltd. ; S.l. : Polygram Music Video [distributor], c1983
LOCATION CALL # STATUS
Con Music VR786.2183 BEE 1 CHECK SHELF
Description 1 videocassette (VHS)(60 min.) : sd., col. ; 1/2 in
Note Title from cover
Recorded live at the Sydney Opera House, October 1st 1983
Contents Contents: Pathetique sonata no. 8 in C minor, op. 13 -- Moonlight sonata no. 14 in C sharp minor, op. 27 no. 2 -- Appassionata sonata no. 23 in F minor, op.57 -- Encore: Chopin grande valse brillante in E flat major, op. 18
Performer Cast: Roger Woodward, piano
Summary "The Sydney Opera House tenth anniversary recital"...opening credits
and the only other 2 things that came up were sound recordings playing chopin and prokofiev, so i guess that's not what you want
but if you want to look it up yourself go to
https://opac.library.usyd.edu.au/one suggestion- it was recorded at the opera house, so maybe you could try asking them if they have a recording or where you can get one