Jon,
thanks for prompt reaction, however in provided pcap unfortunately aren't any sflow data usable by NTA :-( It seems that device is exporting only counter samples (statistics about amounts of packets traversing through device interfaces, pretty much the same information you get by monitoring using strandard snmp).
According to this article: sFlow: Configuring F5 BIG-IP it seems that F5 released newer TMOS 11.4.0 in June, that should bring full sFlow support including packet sampling - the type of info that NTA collects.
If you plan to upgrade to the TMOS 11.4.0, I would be pleased if you could then provide a packet capture once again.
Thanks!