I stopped explaining the raid to new people the moment new people started lying about having done the raid. Before every new part, I ask "has anyone not done this before or isn't comfortable with a certain task" 9 times out of 10, no one responds asking for help. Seven wipes later and I pull up everyone's stats on destiny tracker. 10 times out of 10 there is at least one person with 0 or 1 hard clears. That person is told exactly why they are being booted (for lying, not for sucking) and then booted.