Potty Training 18 month old

[KingstonMom]

So as an update, we tried again the diaper free today, and let dcg run about while I kept a VERY close eye on her. She had two accidents and has not really shown me she understands the concept. She apparantely only pees in the potty at home and has had no accidents as of recently. This makes me wonder why she is not showing this behaviour here.
I am getting fed up with the 'accidents' and decided that I would tell parents we need diapers or pull ups until she shows me she understands more that pee goes in the potty.
Just this evening I get a text msg from my 3 year old dck's dad. He said he noticed Sally sitting on an ottoman with no pants on and has concern because kids touch that and hands go in the mouth etc. He doesnt think this should be happening at daycare (no pants on)
I was kind of taken aback from this comment. His 3 yo girl is NOT potty trained and we tried diaper-less afternoon with her one day (when she was willing) and he thanked me for it!!
This puts me in a position between two families- but also gives me an out as it was not quite working anyways!
What would you do?