I need help deciphering this stacktrace

While running my ios app a user has encountered the following error. It has only happened once and I cannot figure out how to repeat the error. Could someone please interpret the following stacktrace to help me find the cause of the error.

Signal

Unknown Signal Stacktrace (9)

0 LeadsBoard 0x0001b5f2 testflight_backtrace + 142
1 LeadsBoard 0x0001c180 TFSignalHandler + 212
2 libsystem_c.dylib 0x3419d72e _sigtramp + 42
3 libsystem_c.dylib 0x341923ba pthread_kill + 58
4 libsystem_c.dylib 0x3418abfe abort + 78
5 libsystem_c.dylib 0x3419e828 szone_error + 216
6 libsystem_c.dylib 0x341a4f0e szone_realloc + 66
7 libsystem_c.dylib 0x341c60e6 malloc_zone_realloc + 62
8 Foundation 0x3486bcf4 NSZoneRealloc + 32
9 Foundation 0x3486bb40 _NSMutableDataGrowBytes + 336
10 Foundation 0x3486b96c -[NSConcreteMutableData appendData:] + 80
11 LeadsBoard 0x0000fd90 -[DataModelPeopleClass connection:didReceiveData:] (DataModelPeopleClass.m:152)
12 Foundation 0x3486b8f6 -[NSURLConnection(NSURLConnectionReallyInternal) sendDidReceiveData:originalLength:] + 150
13 Foundation 0x3486b822 _NSURLConnectionDidReceiveData + 90
14 CFNetwork 0x35a7406c _ZN19URLConnectionClient21_clientDidReceiveDataEPK8__CFDataPNS_26ClientConnectionEventQueueE + 172
15 CFNetwork 0x35a68fb4 _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 212
16 CFNetwork 0x35a68e36 _ZN19URLConnectionClient13processEventsEv + 70
17 CFNetwork 0x35a68de8 _ZN13URLConnection24multiplexerClientPerformEP18RunLoopMultiplexer + 36
18 CFNetwork 0x35a68d5a _ZN17MultiplexerSource7performEv + 126
19 CFNetwork 0x35a68cd8 _ZN17MultiplexerSource8_performEPv + 8
20 CoreFoundation 0x36487a78 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 12
21 CoreFoundation 0x3648975e __CFRunLoopDoSources0 + 382
22 CoreFoundation 0x3648a4ea __CFRunLoopRun + 230
23 CoreFoundation 0x3641aec2 CFRunLoopRunSpecific + 230
24 CoreFoundation 0x3641adca CFRunLoopRunInMode + 58
25 GraphicsServices 0x35bd441e GSEventRunModal + 114
26 GraphicsServices 0x35bd44ca GSEventRun + 62
27 UIKit 0x352c4d68 -[UIApplication _run] + 404
28 UIKit 0x352c2806 UIApplicationMain + 670
29 LeadsBoard 0x000020fc main (main.m:14)
30 LeadsBoard 0x000020c7 start + 39 

Environment

Device Name: iPhone
Model: iPhone 4
Version: 4.3.5
Language: en_AU (English)
Carrier: Virgin Mobile
Timezone: AEST
Architecture: armv7
Connection State: Wifi 

Check your NSURLConnection delegates, specifically in DataModelPeopleClass.