Through 58 games last year he had 23 points, or an 82 game pace of 33 points. He then caught fire down the stretch in large part due to more offensive opportunity with Turris hurt. He played 2+ minutes more per game in the last 20 or so games, he was given more offensive ice time, and of course he got to play with Stone.
He is a career 10.7% shooter. Last year he shot a career best 14.3% and this year he's shooting a career worst 5.6%. Even at his career average, he would have double the amount of goals this year which would put him on pace for 15+ goals and 35+ points, much closer to what he did last year.
He averaged 1.62 shots per game last year and 1.82 this year, so there's certainly a lack of puck luck involved here; I can recall at least a few great chances that haven't found the back of the net for him.
Ottawa also had an aggressive PK last year which led to a lot of short handed goals [and a lot of PP goals against..]. Being mainly a defensive forward, his offensive numbers benefited from this with 7 goals and 9 points on the PK compared to no points this year.
I honestly don't think he's played poorly this year at all. He's a key piece in their defensive transformation. He's been our best faceoff man, a top PK option, and he continues to play a physical game. A few more goals would be nice but I think he's at least generated a decent amount of chances.
So for me, no, he's not a one hit wonder at all.