"He did a great job too because he was thrown on the wing and then he was at fullback and then he was at halfback, so he did a really good job and I think he'll get a lot of confidence out of that."
The 19-year-old demonstrated his attacking ability midway through the second-half, showing great skill and composure to fire a 20m pass infield to hit Ngani Laumape on the chest for the Warriors' eighth try. Five minutes later, he was at it again when he provided a nice short ball to send Manu Vatuvei in for his second four-pointer of the afternoon.
"He's got a bit of class about him. Not too many people can make that play and he measured that up pretty well and it was a high-quality play," McFadden said.
Captain Simon Mannering was pleased his side went on with the job in the second-half after taking a 28-0 lead into halftime, with lapses in concentration having proved costly in their previous two defeats to Manly and Brisbane.
Watch: NRL Highlights: Warriors blitz Canberra
"That's probably been a trend for us. Not necessarily just after halftime but when we've had a fair run of play we tend to maybe take our foot off a little bit and give the other team a sniff but we definitely didn't do that today which was pleasing," he said.
Conceding three tries in the final five minutes when they were down to 12 men ultimately prevented the Warriors from claiming sixth position on the NRL ladder, but Mannering was unconcerned.
"The end of the game didn't leave too good a taste in my mouth but, hey, there were a few things going against us and it was just unfortunate to let in those points. But we got a win in Canberra which we haven't done in 17 years so we'll take it."
Injuries to Konrad Hurrell (hamstring), Sam Tomkins (corked thigh), and Jacob Lillyman (ankle) and the departure of Leuluai (groin) meant resources were stretched but with the result beyond doubt McFadden was happy to err on the side of caution in the final stages.
"I don't think any of them are that serious. Given the circumstances around the game it wasn't worth risking them or pushing blokes through so we took that opportunity," he said.
The Warriors now look ahead to Sunday's home match against the bottom-placed Cronulla Sharks, with Johnson and Ben Henry [knee], who was a late withdrawal in Canberra, both a chance of returning to action.