I think these days teachers and carers are staying cautious about children's development because we would hate to think that we missed something that could have helped the child get assistance early and made it a lot easier for them to progress in learning and life.
I know as a child carer I would rather refer a child who I even had a slight concern over rather than miss that opportunity for early intervention that could in turn lessen or even correct any problems that were occurring I would rather be wrong than miss something that could help your child.
In saying that I know how tactless some people can be in delivering their opinion I have been on the receiving end of concern expressed about my DD but it is understandably a delicate situation for all involved I have had to tell parents recently about things of concern about their children and I felt so awful doing it.
I am sure everything will be fine for you both and I really don't think that it was anything that you have done and I totally agree that sitting on the mat is a skill which they develop in time believe me I know, I work with 30, 3-5 year olds, so I am sure that it won't be anything serious, if anything at all!!! he may just be an imaginative thinker (I know I have been guilty of thinking big thoughts when I am supposed to be focusing on lectures or training sessions and finding it hard to stay on track with the group
)
hope this makes sense I seem to have rambled I think.