[Dewhitewolf]

Waivers are meant to protect instructors from lawsuits. They are an acknowledgment of the assumption of risk. They do not absolve an instructor who is negligent. This means that an instructor can't use a waiver to shield himself for failing to exercise due care.

To get around a waiver due to negligence, the burden would be on the plaintiff to prove the following four elements:

a duty of care;
a breach of that duty;
harm to the plaintiff;
proximate causation.

Actions by a defendant that are considered intentional and malicious, or intentional crimes, also circumvent waivers.