Turnbull was in no win situation if he endorsed Rudd he would have been ridiculed as a Labor lite and if he didn't he would be called mean spirited.
Interestingly Gareth Evans said Turnbull should have endorsed Rudd,Gareth got a good few years on the UN gravy train after he left politics and there was nothing to show,the comments that Turnbull should have given the nod to Rudd by the Labor party are pathetic ,this was the party that dumped Rudd and heaped criticism on him of how disruptive,chaotic and divisive he was as PM and they wanted Turnbull to endorse him.
No one should ever give endorsement to someone unless they believe in what they are doing and no one should give the endorsement knowing that Rudd would loose the vote for the job all that would have have done is kept Kevin in the lime light warming the bench.