Hard to say without more info. First the more obscure stuff:
- You were both in SC, so it was not mass lock.
- If it happened just sometimes, i would ask if you might have a "vision still obscured" to the destination. Your friend might have cleared the space around a planet and hit the switch, but you did not have clear view yet.
But i think these are oddities. The real question is: how far can your ship jump, and how long jumps does your friends ship plan? It might very well be that his jump range is significally longer, so he keeps jumping to systems your ship can not reach?
If this is not it, i don't know yet. Would have to have more info. And also got to admit, as my friends stopped playing years ago, if something broke in this system in the last years, i would not have noticed. Also, i remember that there was some kind of "out of nav lock" range in old times. If he was too far away, the thing would not work properly. But i don't remember the details for that any more.