I think you are probably ok since there was still 2 1/2 qts in the crankcase. It’s true that a dipstick showing no oil doesnt mean there is no oil at all. If you were just putting around town and the car didn’t overheat, and the oil pressure was ok (the guage read nominal or the idiot light didnt’ come on) there was probably no permanent damage to the engine from this incident.
I’m surprised you didn’t see oil leaks staining the cement under the car where you parked it overnight though.
There were no oil stains; no smoke; no odors. No indications whatsoever that oil was low.
I would check it every other gas fill-up for a while until you get a “feel” of its oil consumption…
I agree with Caddyman. Do not assume that since they found and fixed an oil leak that the oil level will never drop again. If a car leaks a quart of oil every 2,000 miles, it will most likely spot the ground where it’s parked, coat its undercarriage with a film of oil, and/or leave some form of evidence that it has a rather significant oil leak. However, a car can consume that much oil and not leave a bit of evidence behind anywhere because such a rate of consumption is not out of the ordinary for an internal combustion engine.
Just remember to keep the oil checked regularly. You dodged the bullet this time, but might not be so lucky next time. As Caddyman said for the first couple months check it at least once a week or every fill up. Once you’ve figured out whether it’s using/leaking any oil you can probably adjust that to every 500-1000 miles without problems.