This may shock you to hear, but good players can have bad shifts. It doesn't make them a bad player, it just makes them human. Bruins forward Brad Marchand had one of those shifts and it directly led to the Montreal Canadiens tying the game early in the second period.
After Johnny Boychuk made a wonderful defensive play to break up a two-on-one chance for the Canadiens, the Bruins headed the other way and were trying to get into the Canadiens' zone.
Marchand had the puck on the offensive side of the red line. As he cut across, the puck was taken right off his stick by Brendan Gallagher and the Canadiens were off to the races. Making matters worse, the rest of the Bruins were trying to go for a line change. They never really recovered.
Gallagher got a shot off, which Rask stopped, then Tomas Plekanec shot went wide and that was followed by Brandon Prust fanning on an open net from close-range. The puck remained loose, however. Gallagher and Plekanec worked the puck out and Plekanec sent a pass to defenseman Mike Weaver. Marchand was helping in his own end but was at the end of a long shift, he couldn't get to Weaver in time to block the shot, which Weaver drilled from the top of the faceoff circle past Tuukka Rask to make it 1-1. The Bruins were all over the place on that one.
Weaver's goal was the 36-year-old defenseman's second career postseason tally.
There were a lot of bad decisions there and it ended up costing the Bruins the lead. If the Bruins weren't simultaneously going for a line change when the puck got turned over, it may have been a non-issue, but Marchand's turnover left the Bruins scattered. That's a tough way to lose the lead, especially with the Bruins having to find a way to avoid going down 2-0 in the series.