Ok, today I had this happen:
I get contacted with a freelance work offer, in the middle of a big project.
So I say "Only as last resort", and they say "You're it, it's a rush job, we can't get anyone else. - We'll get back to you once the files are in place".
I return to my project.
Then three hours later I get an email saying "It's overdue already, can you send it ASAP?".
I go and check, and sure enough, they had sent an email that the files were ready, a quarter of an hour after that previous mail.

Now, the case is this: Who was in a hurry to get this done? Who knew I was in the middle of something? Who didn't call or text me that the files were ready? Who didn't ask for confirmation of receipt...
They even have a system where they can see when I flag a job as "In progress"... which I hadn't.

Don't rely on non-reciprocal communications for vital messages!
Know whether your message was received or not!
Don't assume the person in the middle of a project will remember to check email... sometimes they have to stop working and go eat, for instance.

Srsly. I think there should be a universal conscription to "get your act together"-camp.
I could use it too.