Ti is talking about the connections at the IEC inlet. The ends of the wires are exposed, therefore there is live voltage present there that if you touched and were grounded, would definitely feel. A better way to do it would have been like this (the left-hand side of the photo):
I cheesed out on the hot connection and just used shrink, but that was because there simply wasn't enough room to use a connector. Ti is saying that at a minimum all of Mikhails connection should use shrink like that and I agree with him.