A Question about Blogging Netiquette

[boobookitty]

Someone has written me to tell me that he has linked to a blog of mine, which is a PR3.
I checked out his blog, and it doesn't look like a spam blog or anything.
So I checked the PR rank and it's NA which worries me. It looks like it's been around long enough and has enough posts to have been indexed, and I worry that it's been sandboxed for some reason.
Normally with a blog like this that has no PR, I would offer to link him up from one of my PR0 or PR1 blogs, but I am afraid to do so with this one.
He's linked to several higher PR blogs with no recips (that I see, they may have ABC recips) and I feel kind of sorry for him, looks like he is trying, but this is a biz after all and I work very hard to appease the google gods.
I don't want to hurt his feelings :=(
Any advice?
eta: I guess one thing I am asking if anyone knows that linking to a (possibly) sandboxed blog will hurt me? And if so, perhaps I should just say thanks and let it go?