MediaWiki suppresses conflicts between edits by the same user, making the newer edit unconditionally override the same user’s older one. This may make sense for manual edits (see T30720#321100 for rationale), but I think it should not be done for automated edits: if a tool editing on behalf of a user has some delay between fetching and editing a page (e. g. because the fetch is batched), and the user manually edits the same page in the meantime, the tool should see an edit conflict instead of discarding the manual edit.

(The term “tool” is a bit fuzzy here – I’m not sure if it should mean “client using OAuth”, perhaps including “client using bot password”, or instead “edit with bot flag”.)

Additionally, I think an edit conflict should also be reported if a tool edits the page between the user loading and submitting the form for a manual edit, but that may be trickier to implement. (The first condition can be implemented by checking if the current client is “a tool”, by whatever definition, whereas the other direction requires checking if the previous revision was made by “a tool”, which we may not know at this point.)