[NCC] Sprint question for the experienced

[n2cu at roadrunner.com]

Maybe I didn't get something in the rules...

Station A calls CQ.
He comes back to station B.
I need station B, so I wait.
Station A completes his QSO with station B.
I wait a second to see if Station B is going to QRZ? or call CQ.
All of a sudden Station X starts calling CQ on Station B's frequency.
I already worked Station X so I go away empty handed ;^(

Why did Station X take Station B's QRG? Just being rude?
--
73,
Tom N2CU <><
K3 #3582