That's interesting. NRL.com match centre says that he missed 7, Mahoney missed 6 and Kikau missed 5
NRL stats have long been inconsistent from source to source.
Generally the contentious ones are the total tackles - as some can come in far too late to be an influence on the tackle, and still be credited with one. Some sources will give a green tick, others will draw a hard line and say "fuck off mate, you've just done a Hindmarsh".
For the life of me though, I do not know HOW you have disparities on missed tackles.
EDIT**
I just remembered. It was placed at Salter Oval - meaning the camera work is not the same as a big stadium (meaning less cameras, and less options to see). My guess is that he may of been credited some that weren't his due to lack of angles available. Given he and Mahoney both wore headgear in the middle - it could've easily been mixed between the two.