[Blood of Tyrants]

Failure of the ground drew to properly pin the landing gear.

[T.B. Yoits]

This is not the first time it's happened to a 787.

From 2022:

https://simpleflying.com/british-airways-nose-gear-collapse-aaib-report/

[T.B. Yoits]

Failure of the ground drew to properly pin the landing gear.

Apparently it's a poor design with two holes in close proximity, increasing the likelihood that the technician would insert the pin in the wrong hole. There was an Airworthiness Directive and Service Bulletin for that and the investigation will show whether or not the corrections were made.