The surviving man wan was Mohammad Stalhoub, a disabled 41 year-old.
http://www.dailystar.com.lb/article.asp?edition_id=1&categ_id=2&article_id=74379
This article, from a Lebanese paper, The Daily Star, also provides a possible name for the Green Helmet man.
"Where is the humanity? Why are these massacres being committed against civilians?" asked Naim Raqa, the head of the Lebanese Civil Defense unit in the nearby village of Jawaya, who was assisting in the rescue operation.
This is in the third paragraph and the first name mentioned in the article so it could indicate the guy who was most visible in the operation.
The baby Green Helmet man was showing off is identified in this article. http://www.guardian.co.uk/israel/Story/0,,1833884,00.html
The youngest, Abbas Mahmoud Hashem, lay on his back with his head turned and his right leg drawn up. A dummy hung on a blue plastic chain round his neck; concrete dust covered his face and hair. He looked about 18 months old.
The house that was bombed was owned by an Abbas Hashem, so the child may have been a nephew since a surviving girl, Noor Hashem, who is his niece, says her mother had rescued her and her sister and then went back into the house to find her three brothers but never returned because they are all dead.
Rhetorical question, but the answer is: because Hamas operates out of civilian populated areas and used these victims for human shields, if not worse.
The article you linked to at http://www.guardian.co.uk/israel/Story/0,,1833884,00.html
has to be one of the most biased I've ever read. I would be foolish to cite them as a reliable source. A sampling: