The suspicion is that G1 GC logging is partly incorrect and/or inaccurate
The attached gc.log file contains the command line args at the top.

1. Line 134:
   [Eden: 2456.0M(2456.0M)->0.0B(2200.0M) Survivors: 0.0B->256.0M Heap: 2456.0M(24.0G)->249.9M(24.0G)]

The survivors contain 256.0m while the total heap contains 249.9m.
This is inaccurate at best.

2. Line 7500
   [Eden: 3568.0M(3568.0M)->0.0B(3216.0M) Survivors: 112.0M->464.0M Heap: 11.3G(24.0G)->8694.0M(24.0G)]

My understanding is that eden is now 3216.0M. When looking at the subsequent
collection at line 7652 the size of eden is now 1992m containing 2520m which means
it's 127% full .This is clearly wrong :

   [Eden: 2520.0M(1992.0M)->0.0B(2144.0M) Survivors: 464.0M->312.0M Heap: 11.0G(24.0G)->10236.0M(24.0G)]


If the eden was resized somewhere between the collections at 7500 and 7652 this should be logged.