I designed today a formula how does just that and even uses a dynamic range
for itself to function...

=AANTAL.ALS(VERSCHUIVING($A$2;0;0;AANTALARG($A:$A)-1;AANTALARG($A$2:$B$2));A
2)>1

where:
AANTAL.ALS = COUNTIF
VERSCHUIVING = OFFSET
AANTALARG = COUNTA

Be sure to be on A1 of the range  (= A2 in my example because row 1 contains
labels). Notice that it takes all the rows in account and only two columns
so

=AANTAL.ALS(VERSCHUIVING($A$2;0;0;AANTALARG($A:$A)-1;2);A2)>1

does the same as the formula above.