Imagine, for example, if you did:What do you mean by that? Doing adjacent parity instead of opposite?
Uw2 Rw2 U2 Rw2 Rw2 U2 Rw2 Uw2
Uw2 Rw2 U2 Rw2 R2 U2 Rw2 Uw2
or something along those lines. I wouldn't know exactly what happened; people can be very creative in doing things wrongly.