You neighbors ice maker line arouses concern.
I doubt the line itself ruptured, unless it was poly.
The smaller the diameter on sched 40, the greater the pressure it can handle.
More likey a self piercing saddle valve was used, they're awful - sold at HD's & Lowes everywhere.
As for the Sharkbites...you'll be the best judge in a year or two as for how effective they are.
I won't use them on potable/high pressure...doesn't feel right making my customers guinea pigs.