Outsourcing led to the British Airways IT disaster?

Over the last weekend, British Airways encountered a nightmare in the form of IT outage that grounded flights for two days . The nightmare isn’t yet over as British Airways may be forced to payout about £150 million in compensation for affected passengers for disruptions even the third day.
Speaking to the Guardian, British Airways CEO Alex Cruz vetted out  that the outage was related to  a power surge at one of its UK-based data centers. The disaster recovery or back-up systems didnot step in as expected which compounded the issue. In 2015, British Airways outsourced some of its operations to Tata Consultancy Services in India. The GMB general union which represents BA workers, pointed out that  the airline’s decision to outsource may have led to the catastrophe.
This was denied outright by Alex Cruz, who insisted that a power surge “had a catastrophic effect over some communications hardware which eventually affected the messaging across our systems.”