Take a look at the goal above and come up with the name in your head that you immediately think is the person most-responsible for this goal being scored. It's Jonathan Ericsson isn't it? By the time the puck gets behind Petr Mrazek, he's the guy right there in front standing by the goalscorer Mark Letestu with his big ol' paws full of nothing but regret for not having prevented the guy right in front of the net from scoring from there.
That's never excusable. You've got to have that spot covered when somebody goes there. Absolutely unconscionable by Ericsson.
Except that's not exactly the case. Yeah yeah, Ericsson isn't perfect and he does make a mistake that helps this goal happen. I've come not to praise Riggy, but to bury him. I'm just saying that the mistake Ericsson made isn't the one people seem to think it was. The idea that Ericsson has to be in front of Letestu or deny him this ice forgets how Letestu got to the front of the net in the first place. Let's take a look at the real culprit here: Landon Ferraro.
We'll start here with the Oilers' zone entry. After Ferraro and Helm both find themselves having to come back through the neutral zone, the Oilers get the puck in on a 3-on-2 entry with Nail Yakupov carrying across the blue line on the right wing side. He has Mark Letestu forcing Niklas Kronwall back to give him that space and also Benoit Pouliot on the far wing to keep things honest.
Immediately after Yakupov gets in, Helm and Ferraro follow suit to get back. Helm curls to the middle and stays high to watch Connor McDavid coming through the middle and Ferraro starts taking an angle on Yakupov near the half-wall. The Oilers' fifth player is Andrej Sekera. He's not too far behind McDavid as a late-man jumping option to take up the middle lane as McDavid slides over closer to Yakupov to essentially take the point.
You'll notice Ericsson's movement from the zone entry brings him immediately back towards the area in front. He's in position to make an immediate move on Letestu if Kronwall screws up, but is also free to release out to the far wing side in case Yakupov threads it across to Pouliot. The problem here is that at the very end of this .gif, you'll notice that Ferraro curls off Yakupov far too early.
Ferraro backs off his man to get into a passing lane that Darren Helm is already covering (insofar as Helm is prepared to defend against McDavid after he receives the pass and not so much that he's able to do much to prevent it). Yakupov immediately notices that Kronwall is still tracking Letestu to the front of the net and that Ferraro has stopped short of the lane necessary to keep him to the outside. At this point, the 4-on-4 that the Wings had been developing breaks down into a 3-on-2 below the tops of the circles.
Here's the issue: on the PK you're always going to have a 2-on-1 somewhere or a 3-on-2 somewhere. The penalty killers' job is to keep that odd-man away from dangerous areas. If Ferraro pushes in on Yakupov, the 2-on-1 that he's creating for the Oilers at that moment is McDavid and Sekera vs. Darren Helm at the top of the zone. Ferraro would have Yakupov, Kronwall would have Letestu, and Ericsson would have Pouliot. The odd-man advantage if Yakupov made a safe play to a guy would be nowhere near the net, giving the defense time to adjust and try to keep that advantage from pushing to the interior of the zone.
Instead, what happens is that Helm is held high long enough to make a pass to Pouliot a real danger, holding Ericsson away from immediately taking Letestu from Kronwall. Kronwall is forced to hand Letestu off in coverage because Yakupov takes the space given to him by Ferraro and starts pushing towards the dot, which would give him a fantastic shooting lane. Kronwall has to prevent this, meaning he has to abandon his positioning on Letestu to go challenge Yakupov. The split-second delay in how this all develops is all the Oilers need to push the manpower advantage directly to Petr Mrazek's doorstep and create this goal.
HOWEVER, JONATHAN ERICSSON ABSOLUTELY DOES MAKE A MISTAKE ON THIS PLAY.
Here's the entire play from the zone entry to the goal again. I slowed down the .gif at the crucial moment. We've already covered that Ericsson's positioning as this play develops makes sense and Ferraro's odd choice to force Yakupov towards the front of the net (combined with the need to worry about Pouliot) is what leads to Ericsson being behind the goal-scorer at the top of the crease instead of in front of him.
However, those split seconds that Letestu is posted in front with his stick down ready for a pass are about three split-seconds longer than he should have been allowed to have his stick in that position without Ericsson chopping down on that thing like Paul Bunyan at a log-splitting jamboree.
There's a good chance that anything Ericsson does to prevent Letestu from putting the puck in from that position causes a penalty and gives the Oilers a 5-on-3 advantage, whether it be from a broken stick on a slash or a cross-checking penalty for an aggressive crease-clearing move. However, when faced with the near-certainty of a goal versus the relative certainty of a penalty, hindsight tells us we'd rather take the chance that the refs wouldn't call something than accept what ended up happening.
Overall, the decision processes by the Wings' players that led to this goal were lightning fast and 90% good. Unfortunately, all it takes is one bad decision to cause a cascade that ends with the puck inside your own net. teams will often get away with mistakes like this, but not as often as we'd like. Detroit made two mistakes that they didn't get away with and it cost them the first goal against in an ugly loss.