I found almost the exact play in the 2013-2014 Redding Study Guide and the ruling is consistent with both options (dead ball spot or previous spot enforcement).
Perhaps I'm misinterpreting the rule but it seems to me at the end of the down, although Team B will begin a new series, the ball "belongs" to Team A.
Rule 2-4-2:
"Belongs to”, as contrasted with “in possession,” denotes custody of a dead ball. Such custody may be temporary, because the ball must next be put in play in accordance with rules governing the existing situation.
The penalty statement reads:
"Live-ball foul. Five yards from the previous spot, or five yards from the spot where the subsequent dead ball "belongs" to Team B."