Wait, so use of partial downloads (say reading from a stream buffer) is legally different than the same use of a full download? (If my connection is fast enough

Wait, so use of partial downloads (say reading from a stream buffer) is legally different than the same use of a full download? (If my connection is fast enough for the second song to _fully_ buffer before the first one finishes playing, does this change anything, since the player is now reading from effectively a "full download"?)