MIMIC IV/hosp/labevents, entry error for same subject and same charttime?

[ahipSQL]

I use labevents data for my study and found something wiered. When I ran the code in python/pandas as below,

df.groupby(['subject_id', 'charttime', 'label']).filter(lambda x: len(x) > 1)

I found same subject_id, at same charttime, same itemid/label but with different data entries

For example, as index 16407 and 16416 in the figure, same subject_id, at same charttime, same itemid/label, but different storetime, different speciment_id, and different value/valuenum. Since these are CSF data, it's not common to perform lumbar puncture twice in a short time period. What do these data stand for and how should I handle them?

Thanks. Merry X'mas & Happy Holiday!!