REST dataloads throw errors that Bulk loads do not.

[prescod]

The REST loader should strictly follow the spec from the Data Loader guide.

Boolean • True values (case insensitive) = yes, y, true, on, 1 • False values (case insensitive) = no, n, false, off, 0

https://resources.docs.salesforce.com/228/latest/en-us/sfdc/pdf/salesforce_data_loader.pdf