As Mac pointed out, becket dances can be more complex/confusing. Removing
a need to separate you from your partner at the end of the dance, allows
for some choreographic flexibility. All the same, most beckets are not
notably more complex/confusing than most improper contras.
My guesses are:
1 - this couple had a bad experience that they associate with 'becket
formation' rather than whatever confounding factors go into making a dance
experience pleasant or unpleasant
2 - was this a contra event (all duple-minors all the time) or a more
varied program? Maybe the couple doesn't like contras much?
3 - Maybe they are confusing it with some other formation (sicilian, 4 face
4, squares, triplets, etc.)
--Ryan Smith