"I was videoing him and he bounced onto a ball and then came back and went through the lining," Mr Rambaud told the Herald.
"He was stuck underneath. My first reaction was to ditch the phone and run in there. I couldn't even hear him crying until I pulled the cover back - then I could just hear him screaming. All I could see was a foot so I grabbed it and pulled him out of there.
"The look of fear on his face was so scary."
Deacon was shaken but not injured. Mr Rambaud went and complained to the manager but took no further action until he posted the video on his Facebook page.
"I just wanted to warn other parents," he said.
"If we hadn't seen him we wouldn't have known he was down there."
Inflatable World manager Gary Adamson explained what had happened to Deacon.
He said Deacon had jumped on to a big inflated ball and bounced back to an area where a supporting pillar stood. The pillar was surrounded by a tarp that covered the join in the inflatable structure. The tarp had lifted and Deacon had slipped through.
Mr Adamson said he had deflated the area in question and checked it all before reinflating it.
A staff member was now stationed close to the area and a height restriction was in place so small children were not at risk of slipping through.
He regretted that Deacon had a bad experience but was satisfied the safety measures at Inflatable World were sufficient.
"It would have been quite scary for him... as soon as I found out it had occurred I went out and had a look. Could it happen again? Yes, probably. But hopefully not. We've hundreds and hundreds of other children through and it's not been a problem," said Mr Adamson.
It is understood safety inspectors had been to the facility today after being contacted by someone who saw Mr Rambaud's video.