I can kind of see it from his point of view, but I don't agree with how he's handled it.
We found it really annoying when dsd's mum insisting on having all the details of our holidays. It wasn't so much the wanting details but it was the "you're not taking her anywhere unless I know xyz" stance that she took. The way dh looked at it was that he was dsd's dad and was going to look after dsd every bit as well as dsd's mum, he should just be trusted with her, just like he trusted her to his x every time he handed her back. Also, she knew that dh was contactable on his mobile 24 hours a day.
At the time, however, had to hand dsd back to her mum and would not be able to contact his x for another 3 weeks. She thought that was perfectly reasonable, and when dh asked her what she'd be doing and where she'd be going with dsd for the 3 weeks he wasn't going to see her he was told it was none of his ** business. Double standards. So I hope you can see where our frustrations came from.
We would never have promised dsd a holiday and then not taken her though because her mum was insisting on details. What did we want to achieve at the end of the day? A holiday with dsd, if that meant providing all the information dsd's mum wanted then so what - the double standards thing was annoying, but there was no reason not to give the details. She even got dh to sign a letter when we went to France saying he would return her passport to his x as soon as we returned, got dh to sign it, dsd to sign it, she signed it and she dragged a friend in the sign it too. All we thought was "we can sign it in blood if you want, but we'll do it so we can get our holiday".