Sam Shakeshaft

I can confirm for minecraft 18w07a

Can confirm for minecraft 18w06a

Confirmed for minecraft 18w03a

Actually,

/teleport @s ~ ~ ~ facing 0 0 0

causes a fatal error in the console.

Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at i.a(SourceFile:147)
	at bob.b(SourceFile:782)
	at bob.a(SourceFile:382)
	at net.minecraft.client.main.Main.main(SourceFile:140)
Caused by: java.lang.NullPointerException
	at aaf.a(SourceFile:2571)
	at aap.a(SourceFile:2159)
	at byf.a(SourceFile:1248)
	at jy.a(SourceFile:71)
	at jy.a(SourceFile:13)
	at ic$1.run(SourceFile:13)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at i.a(SourceFile:146)
	... 3 more

Just ran into this now. I think a better system would be to define a bounding box for the particles

/particle <particle name> <start location> <end location> [speed] [count] [force:normal] [viewers]

The main difference would be that this would allow you to use relative positions for the box, instead of just constants as the current system uses.