Server sometimes crashes with high randomTickSpeed

Steps to reproduce:

Do /gamerule randomTickSpeed 5000, then eventually it will crash. For the first time, I triggered it by pouring a bucket of water, but I can't reproduce that now.

Expected result:

The server doesn't crash.

Actual result:

[11:28:29] [Server Watchdog/FATAL]: A single server tick took 39.93 seconds (should be max 0.05)
[11:28:29] [Server Watchdog/FATAL]: Considering it to be crashed, server will forcibly shutdown.
[11:28:29] [Server Watchdog/ERROR]: This crash report has been saved to: /home/minecraft/snapshot-creative/./crash-reports/crash-2014-07-25_11.28.29-server.txt
Exception in thread "Server Shutdown Thread" java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:886)
        at java.util.ArrayList$Itr.next(ArrayList.java:836)
        at ql.a(SourceFile:761)
        at net.minecraft.server.MinecraftServer.a(SourceFile:358)
        at net.minecraft.server.MinecraftServer.q(SourceFile:381)
        at ox.run(SourceFile:713)