I'll elaborate a bit more on these two.
I think Salo you can blame a bit more than Smith. Not saying you blame him completely, but he did allow 3 goals to Belarus prior to that goal. He in total allowed 4 goals to a "B" team on 19 shots. This was the easiest semi-final I ever saw Canada play against Belarus. It was a foregone conclusion we were winning before the puck drop.
On the flip side, the Swedes fired 47 shots on Mezin and got just three goals. I guess if there is somewhat of a comparison it would be if Carey Price let a goal from outside of the blue line bounce off his head in 2014 in the Latvia quarterfinal game when the score is 1-1 in the 3rd period. That being said, a truly great team would bail out their goalie against a weak team like Belarus, and Sweden - with Sundin, Lidstrom, Alfredsson, Naslund, the Sedins, among others - never helped Salo with any support.
Smith is less to blame here. There was so much wrong with the Oilers in the spring of 1986 that this was more or less a cherry on top, not THE reason they lost. They were down 1-0, 2-1 and 3-2 in the series. They needed overtime in Game 2 just to tie the series. In Game 3 they got outshot 38-19 and lost 3-2. The greatest offense there ever was had 6 shots on net in the 3rd period that game. Then in Game 7 they were down 2-0, had to crawl back, and still had just 6 shots on net in the 3rd period, 24 overall. This is a team capable of dictating the pace of the game and they didn't.
I don't blame Fuhr at all on this one. At least not on this play. That is 90/10% in Smith. There was slight pressure with Lanny McDonald chasing Smith behind the net, but not enough to make a high risk pass in front of your net that banked in off your goalie. Should Fuhr have been more aware? Like I said, I give him 10% of the blame, that's it. A lot less than the Phillips/Emery debacle in 2007, because Emery gets a bit more blame than Fuhr, although that series was wrapped up either way.