Both trains were operating under the recently installed Thales SelTrac CBTC signalling system at the time of incident, and the Minister of Transport Khaw Boon Wan expressed that he was "disturbed" by an initial finding that "critical safety software" was inadvertently removed from the stationary train, possibly due to a malfunctioning signalling circuit, which led to the crash.

[5] There were previous high-profile train disruptions in June 2017 during the testing phase on the North–South MRT line, when it was transitioning to the Thales SelTrac CBTC.

[5] Before this crash, SMRT had originally scheduled full-line testing of Thales CBTC to begin on the East West Line in December 2017.

[2] Many of the injuries resulted from passengers losing their balance and impacting the floor or fixtures, and ranged from vomiting to a broken tooth.

[3] The collision increased public anger and pressure on both SMRT Corporation and Land Transport Authority (LTA),[8] in light of a major tunnel flooding incident weeks prior, which resulted in a discovery that SMRT maintenance workers had failed to perform the necessary maintenance work on its pumps and had falsified records.

[12] Prime Minister of Singapore Lee Hsien Loong admitted that both the tunnel flooding and the Joo Koon accident "hurt public confidence a lot.

[13] Later, Khaw expressed that he was "disturbed" by an initial finding that "critical safety software" was inadvertently removed from the stationary train, possibly due to a malfunctioning signalling circuit, which led to the accident.

[16] Following the incident, SMRT announced that services on the Tuas West Extension (TWE) would be suspended on 16 November 2017 for safety checks on the signalling system.

On 21 November 2017, in a media statement made by Transport Minister Khaw, SMRT and LTA announced that services between Gul Circle and Joo Koon would be further suspended until mid-2018, when signalling upgrades on the remainder of the line are expected to be completed, to prevent another collision in the future.

[19] Following the investigation, SMRT announced that operation hours on the NSEWL would be reduced to facilitate more maintenance works and the complete transition to the CBTC signalling system.