Well, in flags Type 2 and 3 it is explicitely stated "This user violated a casual or implied agreement with me/This user violated a written contract with me" so its not correct to create one if you are not affected by it and flag Type 1 should be used in that case.
Lol. So I had it as easy as trying to create a flag, without finishing it, to know the answer.
This could lead to a curious case analogous to when in a trial the accused is acquitted due to formal defects in the processing. If a DT created the flag without being affected, hypothetically he might not have enough support even if the flag was very well argued because he was not the right person to do it.