I'm inclined to believe in regards to the original contract Nintendo had signed with Ikegami in 1980, which had also included RadarScope, Space Firebird and Sky Skipper, was likely signed by Hiroshi Yamauchi without having reading it first, like it was a gentleman's agreement. The 1990 settlement of the 1983 lawsuit over both DK and its sequel (as arcade machines) probably had Yamauchi feeling shocked over what he believed was Ikegami's betrayal of his trust.

~Ben