He had celebrated his 42nd birthday two days before the January 2 tragedy.
Investigators believe Robert fell 32ft from a balcony when a railing separated from the brickwork. He suffered fatal head injuries. Police are treating his death as accidental.
There were heartbreaking scenes as Robert's daughter Sorcha (12) paid tribute to her dad in poem and song.
And there were smiles, too, as his family remembered his corny jokes, his poor luck backing horses and his eternal optimism.
Special and personal symbols that were brought to the altar in his memory.
They revolved around his passions -- family and GAA, particularly his local Naomh Maur's club, where he was known a hard man on the field and a gentleman off it.
Poignantly, three of the symbols of Robert's life were brought forward by his children.
To the tears of the many hundreds at St Maur's Church in Rush, eldest daughter Sorcha brought a family photograph and watched as it was placed to the right of her dad's coffin.
Mourners were told that Robert's family meant so much to him and he treasured weekends when he could spend the most time with them. Then Naoise (4), who used to call Robert 'Daddy-Cool', brought a box of chocolates to the altar. Her dad used to call her 'Honey Bunny' and had a sweet tooth, those gathered heard.
And toddler Eoin (2) was carried up the aisle with a Manchester City scarf over his shoulder.
Many of the speakers at Robert's Mass told of his passion for life, and sport and his family. The evidence of that was apparent to all through his daughter Sorcha who read a poem to her dad and then later sang The Sun Will Come Out, Tomorrow from the musical Annie.
"Behind the strong faces we're all incredibly sad, because we lost such a great son, brother and dad.
"And we miss all his love, all his hugging and kissing, but we're making up the team although a member is missing," Sorcha read.
So many attended Robert's funeral Mass, including media and telecoms owner Denis O'Brien and Health Minister James O'Reilly, that a large video screen relayed footage from inside the church to the hundreds outside.