It would be diabolical, to change Our Lady's actual words, to support a personal opinion. Even more so, when that opinion is at least erroneous (such as a ball earth). That is the point.
It could be diabolical to take something possibly said innocently, and in ignorance, as deliberate and malicious alteration; the very
fact that you state this c
ould involve something
merely erroneous supports said possibility.
In crayon, and for example, they wouldn't need to "change" anything that was already "changed" via misapprehension i.e. before their will ever entered into it.
S.a. "rash judgment", and "jumping to conclusions" and reexamine your use of words like
would, and
diabolical. Motes v beams.