Comment 5 for bug 1021490

No, quite often people just use those instructions to successfully find the missing .crash file and do attach it to the existing bug. My fault for copying and pasting too much text from https://wiki.ubuntu.com/Bugs/Responses

Incomplete is equivalent to Invalid if it is never resolved. However, Incomplete gives everyone 60 days to find the bug in LP searches before it goes Expired, at which point it won't show up in the default search filter. So using Incomplete is a good way to reduce duplicates.