At 2:53 I establish a 16 pair in R2C7 & R3C7. Either way, a 6 is used in one of those two rows, and it points left to eliminate 6 from Region 1, C3. At 4:50 I place a 6 into Region 4. That eliminates a 6 from three more cells in C3. Where would a 6 go in the third column at that point?
7:30
Excellent!
How did You know that in R9C3 is 6? In 5:00.
At 2:53 I establish a 16 pair in R2C7 & R3C7. Either way, a 6 is used in one of those two rows, and it points left to eliminate 6 from Region 1, C3. At 4:50 I place a 6 into Region 4. That eliminates a 6 from three more cells in C3. Where would a 6 go in the third column at that point?
Good catch on having me explain it though.