While working on BF-39627, I noticed that metrics tracked for the update command under metrics.commands.update may be updated Incorrectly. Namely, the pipeline value is greater than total. One such instance be found in these logs. For example:

"update" : {
    "arrayFilters" : NumberLong(0),
    "failed" : NumberLong(0),
    "pipeline" : NumberLong(133),
    "rejected" : NumberLong(0),
    "total" : NumberLong(56)
} 

According to public documentation, Subtract this value (pipeline) from the total number of updates to get the number of updates made with document syntax implies that total must be greater or equal to pipeline.

We should investigate if we have a bug in the code or if the public documentation is not accurate (we should also check findAndModify while at it).