#1 was a new instructor who was demonstrating having too much forward trim and allowing the helicopter to run onto the ground with forward motion...
# 2 was a checkride for CFI demonstrating a touch down auto. The examiner had a rather large stomach and the student left it too late to flare and thereby attempted an aggressive flare but ran out of cyclic as it hit the instructors belly....they hit the ground fast and the skids "dug in"...
# 3 Actually the third was a "flare" problem in that the instructor was not authorized to conduct touchdown autos and he did a "power recovery" to a hover auto and bounced forward pulling full aft cyclic---had he been to a hard surface, there is a good chance the skids would have spread a little and then skidded not compressed and then sprung up.
#1 - a very convincing demonstration by the instructor - too convincing
#2 - did he pass his CFI ride?
#3 - not authorised for touchdown autos and couldn't even get a power recovery right!
All three instructor errors and rather confirming a dilution of quality and ability in the instructor cadre......