GetUp's anti-Abbott ad

has not "backfired". It has done precisely what GetUp intended. It has made fun, in the nastiest possible way, of the former Prime Minister and achieved massive coverage GetUp did not need to pay for.
Yes, it is defamatory in that it ridicules Mr Abbott and is therefore like to bring further ridicule upon him. However in the context of an election campaign they are going to get away with it - even while the AEC has said they are not a political entity and therefore should be treated like any other non-political entity.
It was a calculated move by GetUp. They almost certainly sought legal advice before they made the video. They almost certainly knew they would have to pull it almost immediately. It cost them a little to make but when you have a war chest the size of GetUp's war chest it doesn't really matter. 
They have done the damage they intended to do. I imagine that at GetUp HQ there is an air of celebration not commiseration. 
GetUp has "apologised" to the surf life savers, indeed Abbott demanded it but they have not apologised to Abbott.
When Abbott was PM he was (and still is) a member of volunteer rural fire team. He was rostered on duty when an emergency was called. He was allegedly the one who drove the fire truck to the location and he spent some hours there fighting the fire. Instead of acknowledging it in the media he was made fun of, accused of only being there for the photo opportunity and more. Like the surf life saving situation that was wrong. It reflected badly on the men he was working with and on volunteers everywhere.
Fire fighters and surf life savers risk their lives to save others. It is something you train for over many hours. It is not something you do for a photo opportunity.  
Election tactics are getting nastier. We had some material appear in our letter box yesterday. It criticised our local Federal MP. I happen to know our local Federal MP. She has actually worked extremely  hard for the electorate. She has worked far more than the 37.5 hours a week that many of her detractors have worked an she has achieved a lot. But of course the electoral material from her main opponent only concentrated on the negatives (as they see them) and  yes - it outright lies about her, especially by the clever ruse of not giving people all the available information. Unfortunately this is a marginal seat. She will almost certainly lose to the liars and we will have someone who must, under party rules, do exactly as she is told. I don't like that. 
Politicians are there to represent us - not a political party. People like Abbott represent not simply his electorate but the wider community. He represents volunteers - knock him for volunteering and make fun of it and you knock all volunteers. We need volunteers. The country simply couldn't run without them. 
My local MP? She's the one who sent flowers to a member of her electorate when her husband died and then invited her to lunch. No, the family isn't a big donor. They aren't influential. They just happen to have a child with a disability who needs constant care and the MP wanted to be sure that care was happening now that the mother is on her own.  It's the sort of "little thing" that means something big but most people will never know about. 
I know, and have known, members of parliament at both state and federal level and across all parties. I have liked some more than others and there are a few I have no time for.
And I have no time at all for an organisation which claims not to be political knocking the long term volunteering of a former Prime Minister.
How many members of Get Up have decades of volunteering under their belts? How many members of Get Up care about the care needs of individuals on a long term basis?  Yes, there will be a few. But unless you are prepared to do that as an individual don't knock those who do.