Overwatch for passengers on a skimmer

This came up in a game last weekend and the decided outcome of a game I was playing. Short version is can a passenger unit on a raider fire overwatch if the raider is charged?

I was playing vs tyrannids and my raider was charged by genestealers. I said I would overwatch my Kabalite passengers and watched as thanks to splinter racks rerolls they decimated the incoming charge. The nid player than said as the charge was against the raider and not against the passengers, they couldn't overwatch. Now this doesn't seem logical but as I have found out, the rules rarely are. So can someone tidy this up for me and even better yet guide me to a source I can use if challenged? I did check through prior answers in the forum but couldn't find it.

Thanks in advance

English malice wrote:

This came up in a game last weekend and the decided outcome of a game I was playing. Short version is can a passenger unit on a raider fire overwatch if the raider is charged?

And the short answer is YES.

The Rulebook wrote:

TRANSPORTS AND ASSAULTS
If a Transport vehicle is assaulted, an embarked unit can fire Overwatch at the attackers out of its Fire Points

That is great thank you. I have no doubt he will now argue the skimmer has no fire points so th rule doesn't count.