Reports API does _not_ return all rows when paging not specified

[dsl101]

The API docs for GET /sheets/{sheetId} say in the pageSize section:

If neither pageSize nor page is specified, returns all rows in the sheet. If only page is specified, defaults to a page size of 100.

and that is the observed behaviour. I created a Report from the sheet, and made the same request against the Reports endpoing, but only get 100 rows.

The API docs for GET /reports/{reportId} say:

If neither pageSize nor page is specified, returns all rows in the sheet. If only page is specified, defaults to a page size of 100.

This looks like a copy / paste from the Sheets endpoint doc (it mentions 'in the sheet' rather than 'in the report'), but the behaviour is different.

Is it the documentation that is wrong, or the API? If the former, how is it possible to request all rows from a Report?