Re: to be on the safe side
Here it means that they want to do the further tests to eliminate the very small potential for error in the diagnosis, to confirm that this case indeed fits the general pattern. There's also an element of reassurance that comes across: there's no need to worry about the tests because they don't think there's anything out of the ordinary here, but they would like to be able to confirm that.
Re: to be on the safe side
Hi Tdol,
Thank you for your elaborate explanation. Now I am the wiser for the situation in question.
Regards.
V.