"Usually, whether a breach is material or minor is determined on a case by case basis, with the court using six different guidelines to make its determination. The six guidelines are
1) the extent to which the breaching party has already performed,
2) whether the breach was intentional, negligent or the result of an innocent mistake,
3) how certain it is that the breaching party will perform the rest of the contract,
4) how much of the benefit of the contract the non-breaching party has gotten despite the breach,
5) the extent to which the innocent party can be compensated and,
6) how difficult it would be on the breaching party if the court were to decide that the breach was material and that the innocent party was under no obligation to perform his side of the bargain.
"[1]
See point 2. My understanding is that ignorance of the law is basically never an excuse, but ignorance of the facts, for contracts, could be[2].
For example, company X could argue they are ignorant of the fact that software Z is intellectual property of company Y, distributed under GPL. If they stop breaching once informed of that fact they can argue it was an innocent mistake.
But in this case Hancom was advertising that it was using the code under the GPL, so, they certainly can't claim ignorance.
1) the extent to which the breaching party has already performed,
2) whether the breach was intentional, negligent or the result of an innocent mistake,
3) how certain it is that the breaching party will perform the rest of the contract,
4) how much of the benefit of the contract the non-breaching party has gotten despite the breach,
5) the extent to which the innocent party can be compensated and,
6) how difficult it would be on the breaching party if the court were to decide that the breach was material and that the innocent party was under no obligation to perform his side of the bargain. "[1]
See point 2. My understanding is that ignorance of the law is basically never an excuse, but ignorance of the facts, for contracts, could be[2].
For example, company X could argue they are ignorant of the fact that software Z is intellectual property of company Y, distributed under GPL. If they stop breaching once informed of that fact they can argue it was an innocent mistake.
But in this case Hancom was advertising that it was using the code under the GPL, so, they certainly can't claim ignorance.
[1]https://nationalparalegal.edu/public_documents/courseware_as...
[2]https://en.wikipedia.org/wiki/Mistake_(contract_law)