Inconsistency between operation structure returned by horizon and documentation

[salessandri]

The particularly applies to a path_payment operation.

In the operation's documentation there are two amount fields listed: amount (destination amount) and source_amount.
But in the document returned by horizon's REST API (and also in the js SDK), the source_amount field doesn't exist and there is a path field that is not described in the documentation.
Here's a link to a path_payment operation: https://horizon-testnet.stellar.org/operations/34806814398746625