Really though do you want him in a program that expects 5 year olds to have well developed fine motor skills. That may be the first flag that it isn't a very developmentally appropriate program.
I don't know, it doesn't seem all that unreasonable to expect a kid at 4.5 to be able to make a mark in box. DS was doing it and couldn't generate enough pressure to have the tester see it with a regular pencil. Plus, isn't it the point of gifted programs to not be developmentally appropriate - it expects the students to be beyond what is in the traditional classroom. By all accounts, tester, pedi, and teacher, are now in agreement that he is below developmental and its causing tension as it is at odds with his other skills. So its not the test or the program, we need to get him help.
I do like your approach of non pressure, seems like it could be quite effective to wait till they come to you and also offer your help as an option. Although as I mentioned in my aha post to Grinity, I did not realize that he was asking for help, we just didn't understand it!