2 (b) That's wrong. The requirement is that the accident would not have happened without negligence, but even on the brief facts given, it can easily be seen that a high pressure hose might become detached without any negligence on the part of the defendant - for example, because of a hidden defect in the machinery, or an unexpected surge of air pressure.
When deciding this case, the court decided that in these circumstances, res ipsa loquitur could not apply.