Server generates a FATAL log message with a NullPointerException

I saw a FATAL Level message in my logs. Logs: 

. Apparently, the player dying from a spider somehow generated a NullPointerException... The server kept running though. Don't think anyone will be able to reproduce it, but still sending a bug report, because it's a bug.

UPD: I saw this message once more, this time the player suffocated in a wall. Given how often the error happens, it actually may relatively somewhat be reproducible a bit. Updated logs: 

.

[21:31:22] [Server thread/FATAL]: Error executing task on Server
java.lang.NullPointerException: null
	at wc.b(SourceFile:208) ~[server.jar:?]
	at vv.a(SourceFile:897) ~[server.jar:?]
	at wh.a(SourceFile:475) ~[server.jar:?]
	at xb.a(SourceFile:835) ~[server.jar:?]
	at pl.a(SourceFile:122) ~[server.jar:?]
	at pl$b.a(SourceFile:18) ~[server.jar:?]
	at ld.a(SourceFile:21) ~[server.jar:?]
	at sj.run(SourceFile:18) ~[server.jar:?]
	at ahq.h(SourceFile:144) [server.jar:?]
	at ahu.h(SourceFile:23) [server.jar:?]
	at ahq.v(SourceFile:118) [server.jar:?]
	at net.minecraft.server.MinecraftServer.aX(SourceFile:713) [server.jar:?]
	at net.minecraft.server.MinecraftServer.v(SourceFile:707) [server.jar:?]
	at ahq.c(SourceFile:127) [server.jar:?]
	at net.minecraft.server.MinecraftServer.u(SourceFile:692) [server.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:647) [server.jar:?]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_101]