The importance of Pre-scanning & continuous scanning is paramount in this clip, we never like to see a player get injured but it does happen. 

You often hear coaches asking their defensemen to look up ice before coming out from behind the net,  this will help the defensemen identify any threats while still being under the protection of the net. Once they step out the other side, they are vulnerable to a "hunting" forward with bad intentions accelarating downhill looking for the big hit or simply skating into trouble.. 

If Nurse has a good pre-scan (long enough to gather relevant information i.e. Reeves is on ice and incoming) he may have decided to use the net to reverse flow or rim the puck instead of wheeling the net into trouble.

Keeping his "head up" the whole time isn't possible, he has to look down to collect the puck off the boards cleanly, however cycling between eyes up & eyes down needs to be implemented here. Having his eyes down for "one one thousand...two one thousand...three one thousand" without a quick peek is probaly just a little too long at the NHL level where everything moves so quickly.

We all know Nurse is a really good player, this isn't to take anything away from him, it's simply a teachable moment for young players who may need some evidence to understand why coach keeps reminding them to use a shoulder check and scanning on retrievals.