I cannot reliably reproduce this issue, but what I did is following:

• load a session having a QC repository with a checked out gerrit patch (which added a new pri file, modified a pro file)
• modify the file(s) of the patch (have both open splitted editor window)
• amend the former patch, commit and push it
• on the cmdline: checkout the original branch and reset it hard to HEAD
• switch back to QC
  • QC states there are changes inside the pro file -> "Yes, reload"
  • QC states the pri file has gone -> "Close" (but click Close not before you've seen that the reparsing of the reloaded pro file has been triggered)

I had QC crashing here, but as said, I could not reproduce this again.. maybe you'll see sth inside the backtrace (crash happened in Thread 1)