Exercise 2 solution

A bowline can loosen when shaken slack, especially in stiff or slippery rope. If it mattered, leave a longer tail and add a backup, such as a stopper knot on the tail. A clove hitch can loosen or slip if the pull changes direction, which is why it is not trusted for important loads without a backup.
Takeaway: test knots under realistic conditions and add backups where failure matters.