There is not necessarily any certainty in VAR as a company and as the suitor, no equity arb desk will regard this as a done deal IMHO. Discount to the offer price may even be greater than the sell off in SRX on Friday down 1.3% to $27.4 AUD IMHO.
Varian has a history which is even found in a number of Court cases, some are even outlined on Wikipedia. My hope is for an alternative bid. https://en.wikipedia.org/wiki/Varian_v._Delfino