"No spying took place and nothing was stolen."
No.
Just one example from The Economic Espionage Act of 1996
ยง 1832. Theft of trade secrets
(a) Whoever, with intent to convert a trade secret, that is related to or included in a product that is produced for or placed in interstate or foreign commerce, to the economic benefit of anyone other than the owner thereof, and intending or knowing that the offense will , injure any owner of that trade secret, knowingly--
(1) steals, or without authorization appropriates, takes, carries away, or conceals, or by fraud, artifice, or deception obtains such information;
(2) without authorization copies, duplicates, sketches, draws, photographs, downloads, uploads, alters, destroys, photocopies, replicates, transmits, delivers, sends, mails, communicates, or conveys such information;
(3) receives, buys, or possesses such information, knowing the same to have been stolen or appropriated, obtained, or converted without authorization
I suggest people take a closer look at subsection (3)
"The holder of the information in this case was Stepney"
None of the information transferred was his intellectual property.
"And if that is the case, nobody can claim that Ferrari were not responsible for the plans and information being in McLarens hands (but of course they can claim that McLaren broke rules/laws by accepting them).
You have to apply the same rules to everyone. You cannot chop and change them to suit."
Look at the EEA:
the term 'trade secret' means all forms and types of financial, business, scientific, technical, economic, or engineering information, including patterns, plans, compilations, program devices, formulas, designs, prototypes, methods, techniques, processes, procedures, programs, or codes, whether tangible or intangible, and whether or how stored, compiled, or memorialized physically, electronically, graphically, photographically, or in writing if --
(A) the owner thereof has taken
reasonable measures to keep such information secret
Should owner be held responsible for the theft of trade secrets with the intention of injuring when reasonable measures had been taken to keep that information secret?