It seems entirely possisble that an insect could have hatched or pupated in that timeframe for example. If you kill an organism soon after collecting it you are preserving its state. If you rear an insect for months and then kill it you should no longer mark it as wild. This is not a novel question, there are plenty of threads describing more or less exactly this and a clear majority opinion that any organism which has been held in captivity for an extended period of time should be marked as captive. See e.g.
https://forum.inaturalist.org/t/captive-raised-caterpillar-observations/31361
https://forum.inaturalist.org/t/do-terrarium-observations-count-as-captive/33380/
https://forum.inaturalist.org/t/long-term-observation-of-a-pond-water-community-casual-or-not/
https://forum.inaturalist.org/t/captive-cultivated-or-wild-on-rearing-larvae-etc/19773