Seeing this in consulting/ contract dev too. People come to me with “80% done” but in reality it’s the 80/120 rule, the last 20% takes 120% of the time the project should have taken.

Ah the classic:

"That will be about 40 hours work".

"Well I've done 80% of the work already, so-"

"Oh, then that will be about 80 hours of work".