Why does GC logging show events where the sys time is greater than the user time?

Issue

• GC logging shows a collection where the sys time is greater than the user time:

[GC pause (G1 Evacuation Pause) (young), 189.8414654 secs]
   [Parallel Time: 189836.0 ms, GC Workers: 6]
      [GC Worker Start (ms): Min: 2998769103.9, Avg: 2998769103.9, Max: 2998769104.0, Diff: 0.1]
      [Ext Root Scanning (ms): Min: 3.0, Avg: 3.1, Max: 3.2, Diff: 0.2, Sum: 18.5]
      [Update RS (ms): Min: 3.9, Avg: 1935.0, Max: 2321.3, Diff: 2317.3, Sum: 11610.1]
         [Processed Buffers: Min: 36, Avg: 103.0, Max: 143, Diff: 107, Sum: 618]
      [Scan RS (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.2]
      [Code Root Scanning (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
      [Object Copy (ms): Min: 186632.0, Avg: 187311.5, Max: 189828.7, Diff: 3196.7, Sum: 1123868.7]
      [Termination (ms): Min: 0.1, Avg: 586.3, Max: 879.5, Diff: 879.5, Sum: 3517.8]
         [Termination Attempts: Min: 2, Avg: 205.3, Max: 348, Diff: 346, Sum: 1232]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.1]
      [GC Worker Total (ms): Min: 189835.8, Avg: 189835.9, Max: 189836.0, Diff: 0.1, Sum: 1139015.4]
      [GC Worker End (ms): Min: 2998958939.8, Avg: 2998958939.8, Max: 2998958939.8, Diff: 0.0]
   [Code Root Fixup: 0.1 ms]
   [Code Root Purge: 0.0 ms]
   [String Dedup Fixup: 1.9 ms, GC Workers: 6]
      [Queue Fixup (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
      [Table Fixup (ms): Min: 0.0, Avg: 1.2, Max: 1.7, Diff: 1.7, Sum: 7.0]
   [Clear CT: 0.5 ms]
   [Other: 3.0 ms]
      [Choose CSet: 0.0 ms]
      [Ref Proc: 0.3 ms]
      [Ref Enq: 0.0 ms]
      [Redirty Cards: 1.3 ms]
      [Humongous Register: 0.1 ms]
      [Humongous Reclaim: 0.0 ms]
      [Free CSet: 0.3 ms]
   [Eden: 2544.0M(2544.0M)->0.0B(2848.0M) Survivors: 528.0M->224.0M Heap: 4763.6M(60.0G)->2228.7M(60.0G)]
 [Times: user=144.21 sys=221.51, real=189.84 secs]