Aside from their having matching turned off at the Y-DNA12 level, someone might match you at a higher testing level but not Y-DNA12 because the genetic distance is more than the amount allowed for Y-DNA12 but not the higher level.

For example, kit B193 has mismatches with kit B175 at DYS393 and DYS385. Each mismatch has a genetic distance of one for a total genetic distance of two. This is more than the amount allowed for a Y-DNA12 match. However, they do not have additional mismatches on the Y-DNA13-25 panel. Therefore, the genetic distance for their Y-DNA25 match is also two. As a genetic distance of two is within the limit for Y-DNA25 matching, they will show as matches in that category.

Example: Genetic Distance of Two
Kit Surname Hg D
Y
S
3
9
3		 D
Y
S
3
9
0		 D
Y
S
1
9		 D
Y
S
3
9
1		 D
Y
S
3
8
5		 D
Y
S
4
2
6		 D
Y
S
3
8
8		 D
Y
S
4
3
9		 D
Y
S
3
8
9
|
1		 D
Y
S
3
9
2		 D
Y
S
3
8
9
|
2		 D
Y
S
4
5
8		 D
Y
S
4
5
9		 D
Y
S
4
5
5		 D
Y
S
4
5
4		 D
Y
S
4
4
7		 D
Y
S
4
3
7		 D
Y
S
4
4
8		 D
Y
S
4
4
9		 D
Y
S
4
6
4
B193 Sypline I-M170 12 24 14 10 14–14 11 14 11 12 11 28 17 9-10 11 11 25 14 19 30 14-15-15-16
B175 Sypline I-M170 13 24 14 10 14–15 11 14 11 12 11 28 17 9-10 11 11 25 14 19 30 14-15-15-16
B132 Sypline I-M170 13 24 14 8 14–14 11 14 11 12 11 28 17 9-10 11 11 25 14 19 30 14-15-15-16