You're using awfully strong language for a split second decision. Gavrikov and Clarke combined to creat the turnover and Dubois has it for less than a second before the puck is turned over again back to Washington.
He didn't "went" anywhere, he was like 3 inches behind breaking up the pass again.
Is it not a full line error? Clarke was the furthest one back of the other 4 players on the ice.
Just out of curiosity in your estimation what is the "correct" way for him to have played that 2 second (at best) stretch of the game?
Specifically what should he have physically done?
I am not going to dissect the whole thing, its a rarity. Dubois made a dumb decision and it cost the team. I will address Clarke here because that's what we are talking about.
He is already out of position in the 2nd pic you posted, but ideally he stays right there until the puck is going to be clearly exited smoothly. Its likely just unfamiliarity with Gavrikov and Dubois tendencies.
I would say its certain language, not strong. Basic defense, taught in camps, clinics and by coaches alike, tells you that you never want to be parallel to your defensive partner, you ideally want to be staggered because one pass can beat you both in a split second. Undoubtedly thats why Clarke hung his head there, he knew he cheated and lost.
And its not a split second decision, its choosing to ignore a fundamental part of the position in favor of a scoring chance. Happens all the time with big point producing defenders. You have to allow room for something to go wrong as a defenseman. Any number of things can happen on that kind of play. It happens a dozen times every night. That pass could have been tipped into Gavrikov's skates, Gavrikov could have whiffed his next pass, a defender could have made a great play - you don't leave your position because Dubois might blow a tire or try to force a backhanded pass into traffic. Somebody has to be the safety valve in case something goes wrong, and on that play Clarke was that guy but he cheated.
Watch the breakouts in the next few games, and you'll see staggered defense partners and somebody holding back. Its just a matter of routine. This is just something that young puck movers need to learn, and it isn't "real" until it is.