None of the StarWars OXPs are mine. I think it's Charlie's work.
But anyway, if shuttles get assigned one of the two current shuttle AIs (I guess fallingShuttleAI if they are launched from the station, and risingShuttleAI if they are launched from the planet), it shouldn't matter which AI they have in their shipdata.
So my guess is that the problem only arises if the Lambda Shuttle is spawned as a trader, which is its second
role in shipdata. Traders probably don't get any AI by default, so the non-existing shuttleAI would be called, leading to an error.
EDIT: now I'm confused. According to autoAImap.plist any trader gets route1traderAI, just like every shuttle gets fallingShuttleAI if auto_AI is true, which is the case with the Lambda Shuttle. So I don't see how the AI defined in shipdata could ever be used. There shouldn't be an error.
EDIT2: By the way, the Lambda Shuttle is too big to dock. Does perhaps bigships.oxp reset the AI of a trader to the one in shipdata, if it can't assign the appropriate bigshipsAI?