Multi-account CloudTrail S3 object ownership

By default, an S3 object is owned by the identity that uploaded the object. Every bucket and object in Amazon S3 has an owner, the user that created the bucket or object. The owner of a bucket or object cannot be changed. However, if the object is overwritten by another user (deleted and rewritten), the new object will have a new owner.

However, as of October 2nd, 2020, you can now change the object owner on upload. See here for details:

https://aws.amazon.com/about-aws/whats-new/2020/10/amazon-s3-object-ownership-enables-bucket-owners-to-automatically-assume-ownership-of-objects-uploaded-to-their-buckets/

And:

https://docs.aws.amazon.com/AmazonS3/latest/dev/about-object-ownership.html

But the default behavior of S3 remains unchanged.