They said they'd be back in an hour (11:15)- it's now 1:30PM, and they haven't shown up.
Ah ha, all is changed- the garage slab and footing at the end of the block was ready, so they decided to get a big truck and split the load, but that footing is taking 1/2 again as much as estimated (same clay flowing problem) and they need another truckload (10 yards) so they're doing that one by pumping and then the big truck, pump, crew, etc... will cruise to this end of the block and do my pour.
I'd walked down there to see if the contractor was there, and found the concrete guys. And then I got a delayed voicemail telling me what was going on, after I'd found out what was going on from them.
So, it's under control. And because there'll be plenty, and they're pumping, I'll get the permanent pipe filled. I'd planned to have it open with gravel underneath as a drain, but given the conditions in the bottom of the hole, trying to have it drain is futile, so...