No matter how highly Karl valued the opportunity, he simply couldn't let Nora take such a risk.
Even though he and Ian always bickered the moment they saw each other, deep down, they still greatly admired and respected each other. Putting aside the fact that he and Ian both held each other in high esteem, just the relationship between Tanya and Nora alone was already…
Karl thought of how Tanya had reacted when he called to ask her to get in touch with Nora for him. His daughter had kept asking things like: "Is it dangerous?", "Are you sure it won't be dangerous?", "Is there no danger at all?", and so on. Karl had guaranteed that he would never let Nora get even a scratch in the incident.
Now that things had turned out like this, who knew what the Hitman League might do to them?
If Nora got hurt, how was he going to answer to his daughter?