In the episodes opening, when Quark brings kanar for the Cardassian's coming to the station, he places a bottle on a table, just as the camera switches away. When the shot switches back to Quark he is just turning back from the table to deliver a line to Dax. He then appears to turn to Sisko and the shot switches to Sisko. Sisko is holding the bottle, though he appears to be across the room from Quark and the table where the bottle was placed.
The crew of the Defiant observe a comet near to the gamma quadrant exit to the worm hole. The comet has a tail - comets only develop tails as they approach a star. The star heats up the comet, which produces a tail of water vapor which always points away from the star. In addition, the speed of stellar objects like comets are such that ships would've detected it on their sensors months or years prior the episode, and would've known that the comet would've come close to the wormhole.