The ATSB data base is a wonderful thing, here is the report. It seems like there should have been enough separation. It is possible to lose control on takeoff without wake turbulence being involved. Not suggesting that happened but it is a possibility.
Turbulence/windshear/microburst involving a Mooney M20J, VH-LOB, Wagga Wagga, New South Wales, on 6 June 1994 | ATSB
WWW.ATSB.GOV.AU