Petan is a 24 year old forward, not a 19/20 year old D.
Also, you didn’t answer the question.
I answered your question in that Bobby Mac's comment about Sandin was based on watching him play in the NHL. His comment about Liljegren was based on second hand information.
That second hand information may or may not be accurate. Almost a year to the day before Bobby Mac's comments, Dubas was saying that Liljegren had been playing great and had it not been for the injury they were hoping he would be competing for a spot in the lineup later that season. Anyone with any sense knows that was complete nonsense. Months later Dubas and .Keefe both stated that Liljegren had been playing poorly at the time and costing the team games. It is likely that the comments were instead in a hope in increase his trade value. They were negotiating with LA over Muzzin, Friedman has said that LA didn't want Lilly (no the trade would not have included the same other parts if Liljegren was included instead of Durzi, so no it is unlikely that LA felt that Durzi was better than Liljegren), and in the weeks before the trade Dubas said that Sandin was not tradeable without mentioning Liljegren. Months later after Liljegren improved Dubas added Liljegren to the not available list.
At the same time all the same characters on here and on twitter were saying that Liljegren was playing amazing last fall - best D on the team by far - when the people who are experts at evaluating prospects, including a retired scout I know well who goes to almost every Marlies home game, were saying that he was playing poorly - or worse. Then this fall all the same characters on here and on twitter were saying that Liljegren was having a great camp when anyone with a brain knew that he was having a terrible camp. So I don't really give a shit about the claims people like you make, or the kind of claims that Bobby Mac might hear second hand because you guys have cried wolf way to often and lie about Liljegren incessantly.
I've watched Liljegren play. Pre-draft, summer showcase, rookie tournament, 1st preseason, first year on the Marlies regular season, at the WJC, during the playoffs with the Marlies, second preseason, second year on the Marlies regular season, second year on the Marlies during the playoffs, 3rd preseason, and this year on the Marlies. In total I think it is 26 games live and more than 50 more on tv.
I've watched Sandin play in his 1st and 2nd preseason, first and second year on the Marlies regular season, at both WJCs, during the playoffs with Marlies, and his 8 games with the Leafs. In total I think it is 12 or 13 games live and close to 50 more on tv.
I don't think watching the games on tv is useful for evaluation. But I have gone to games where my only purpose was to evaluate either Liljegren, Sandin or both and all I did was focus on them when they are on ice. Nor did I have a bias against Liljegren (who was my favorite prospect ever going back a year and a half before his draft, and remains a prospect I love after changing my assessment to be in line with experts) or a bias in favour of Sandin (who I thought of as small slow skating LHD who was probably picked because he played in the Soo and was a poor pick at the time - and hence didn't bother to watch him at the summer showcase or rookie tournament).
I haven't watched them play enough this season on the Marlies to say who has been better. Some AHL games on tv which I don't care about and they played in 2 of the 3 games I went to. Neither played November 29th, but they both played on the 30th and December 4th. To be honest (unlike in previous years) I wasn't impressed with either in either game (but Brooks had improved a surprising amount).
But again - I don't care who plays better in the AHL. As I have always said on here - if they can produce at ES on the Marlies they will get a shot (and they are unlikely to get such a shot until they do). But that is just to get the shot and has nothing to do with your ceiling in the NHL. Sandin has produced at ES in the AHL from his first game. Liljegren had never produced at ES in the AHL until around 9 games ago - and usually when that happens it is a lucky streak (I guess we will see in the second half). But regardless I am happy for him. I think he deserves at least a game or two in the NHL to see where he is at.
Regardless there is no reason to change my assessment of him of being a potential 4 - 6D, while Sandin is a potential top-pair. Liljegren has some better tools. Sandin has a much better toolbox. The NHL is what counts, but don't worry 5 years down the road you can regale people about the season you feel Liljegren was better than Sandin on the Marlies.