Res Ipsa Loquitur

Q.
What is 'Res Ipsa Loquitur'? How does it be used in defence?

A.
Res Ipsa Loquitur carries the meaning of 'the thing speaks for itself'. An example is in medical malpractice - a cotton swap being left inside the patient's body after a surgery is a clear Res Ipsa Loquitur case of negligence.

Go here to read a very good write up on Res Ipsa Loquitur by Rottenstein Law Group.

However, in a defence of tortuous claim, how is this principle of clear evidence of wrong, be used as a defence?

A defendant may argue that res ipsa loquitur does not apply because the event that caused the plaintiff’s injury was an inevitable occurrence that the defendant could not have prevented. An inevitable occurrence also defeats res ipsa loquitur because the defendant lacked control over what caused the injury.

For example, a case of an road accident had gone wrong in operating theater that caused eventual amputation of one of the legs of plaintiff. The pieces of bone remnants were left inside the patient with infection, this part should have been prevented in surgical clearance of the wound, but did not. Therefore, it was Res Ipsa Loquitur to prove negligence of the part of the surgeon who operated on the patient.
On the other hand, the defendant - surgeon, can use the principle of inevitable occurrence that pieces of remnant had to be left behind because the wound was too messy. Due to the decision not to cause further harm to the patient, they left the remnants of bone during the surgery. Later on, due to infection, they had no choice but to amputate the leg. It was Res Ipsa Loquitur that bone left behind due to surgical difficulties had caused infection and thereafter resulted in amputation of the leg later on.
In such situations, the principle of Res Ipsa Loquitur was used both as attack and defense.

For the attack - bone remnants were clear proof of negligence of surgeon. The remnants should have been cleared.

For the defence - the bone remnants had to be left behind due to messy wound, and further harm inflicting patient. Hence, the thing speaks for itself - bone remnant was left behind to avoid further harm. It was inevitable.

Ref:
Own account.
http://www.rotlaw.com/legal-library/what-is-res-ipsa-loquitur/