In Hive, can Beetle hop over to another lane?
No, the one hive rule is continuous, even during a move.  At least in the version of the rules that I have, the second example under the One Hive rule states


  Moving the black Queen Bee to a position where it re-links the Hive is
  also an illegal move as the Hive is left unlinked while the piece is
  in transit.


This would apply to your beetle move as well, since while it was in transit, it would not be connected to the hive at all.