You're lucky he was still in a 'Conda. I've seen them magically switch ships in the middle of deep space.
One that I have quite regularly is that I'll be doing a mission, get the "incoming hostiles" message and then I'll get an "I've travelled a long way for what's in your hold" message.
I'll flip through my list of contacts and it'll turn out that the message came from, say, a Cobra or an Adder and I think "Well, it's your funeral".
I'll then allow myself to get interdicted, drop out of SC and... the Cobra/Adder has magically transformed itself into a Clipper or an Annie.
*le sigh* [sad]