The panel was talking how Petro has won at every level and if he gets his 2nd Cup, he's got a HOF resume. Tough to disagree. Even without the individual hardware, he'll be one of the best of his generation.
That resume would be 2 Cups (with two teams), 2 gold medals in best-on-best international tournaments, a world junior gold medal, and a 3-time 2nd-team NHL All Star (end of year voting, not all star games). The golds with Canada are a bit of a double edged sword. Those teams were loaded and he wasn't the main contributor to success, but making Team Canada in those years was a huge accomplishment.
Where does that put him in the rankings of his generation?
Keith, Doughty, and Hedman are consensus top 5 D in this generation and should all be first ballot HOF guys IMO. Each has individual hardware, multiple seasons recognized as an NHL All Star at the end of the year and 2 (or in Keith's case 3) Cups as a #1 D. Karlsson doesn't have the Cups, but he has 2 Norris trophies (plus two 2nd place finishes) and the first 100 point season by a D man in ages that will likely win him Norris #3. He should be a first ballot guy IMO.
After that group. I think it would come down to Letang vs Petro for 5th of the generation. I'm not putting Burns, Carlson, or Josi ahead of them. Maybe Weber had a more dominant peak, but he never won a Norris and fell short of the Cup win. Right or wrong, Cups matter and I have a hard time saying that a guy without a Norris win should be ahead of 2 other non-Norris winners who were the #1 D for two Cups. I'd put Weber below them, but I get the argument that he should be ahead.
At worst, I'd say that another Cup puts him at #7 in the generation and could put him as high as #5 depending on what you value. He's 3 years younger than Letang and Weber is retired, so he has more time to pad the resume too.
Personally, I'd like to see an individual award (or a top 3 finish for Norris) for the 5th best D of a generation to get into the HOF. I get that being the #1 D for two different Cup-winning teams is a complete rarity, but a good chunk of that stat is simply the reality that teams almost never let #1 Cup winning D go to another team. What is the sample size of Cup-winning #1D who even went to another team while still young enough to play #1 minutes?
If he wins another Cup and gets in, I won't be upset. I love the player and I don't think he'd be the least deserving guy in there. But I think the resume falls a touch shy unless he does something else substantial or gets himself to a couple decades of service in the NHL.