What are the results of inserting a crimp connector into the crimp tool facing the wrong way?

If you insert a crimp pin incorrectly, the ratcheted crimp tool will not sufficiently crimp the tabs. As a result, the wire may not fully conduct with the pin and the pin will be damaged.

Explanation:

The general theory for crimping all types of connectors is to strip a little bit of insulation off the wire. Then, put the connector into a suitably sized space in the jaws, insert the wire, and crimp it down. For non-ratcheting pliers, it's suggested the connector be re-crimped with the next smallest hole in the jaws.

A good crimp connection is gas tight and won't wick: it is sometimes referred to as a "cold weld". Like the solder method, it can be used on solid or stranded conductors, and provides a good mechanical and electrical connection.