See - sc.judiciary.gov.ph/jurisprudence/2012/october2012/168987.pdf
"x x x.
Lastly, the Court finds petitioner's claim that only herein respondent,
(third-party defendant before the trial court) Rainbow Tours and Travel, Inc., should be made liable to respondents Lao Lim and Go, to be untenable. They have acted together in creating the confusion leading to the erroneous cancellation of aforementioned respondents' confirmed bookings and the failure to inform respondents of such fact. As such, they have become joint tortfeasors, and in Loadmasters Customs Services, Inc. vs. Glodel Brokerage Corporation, the Court elucidated thus:
x x x Where there are several causes for the resulting damages, a party
is not relieved from liability, even partially. It is sufficient that the
negligence of a party is an efficient cause without which the damage
would not have resulted. It is no defense to one of the concurrent
tortfeasors that the damage would not have resulted from his negligence
alone, without the negligence or wrongful acts of the other concurrent
tortfeasor. As stated in the case of Far Eastern Shipping v. Court of
Appeals,
x x x. Where several causes producing an injury are concurrent and each is an efficient cause without which the injury would not have happened, the injury may be attributed to all or any of the causes and recovery may be had against any or all of the responsible persons although under the circumstances of the case, it may appear that one of them was more culpable, and that the duty owed by them to the injured person was not the same. No actor's negligence ceases to be a proximate cause merely because it does not exceed the negligence of other actors. Each wrongdoer
is responsible for the entire result and is liable as though his acts were the sole cause of the injury.
There is no contribution between joint tortfeasors whose liability is solidary since both of them are liable for the total damage. Where the concurrent or successive negligent acts or omissions of two or more persons, although acting independently, are in combination the direct and proximate cause of a single injury to a third person, it is impossible to determine in what proportion each contributed to the injury and either of them is responsible for the whole injury. Where their concurring
negligence resulted in injury or damage to a third party, they become joint tortfeasors and are solidarily liable for the resulting damage under Article 2194 of the Civil Code. [Emphasis supplied]."
