I've seen Michio Kushi smoke, and I know two of his sons:
Larry ("best friends" in HS with the son of a vegan friend of mind)
and Norio (who, with his wife and family, used to attend meetings
of both the Boston Vegetarian Society and Boston EarthSave).

Close vegan friends of mine have said to me that they have
PERSONALLY OBSERVED Michio Kushi smoking.

I have visited the Kushi estate in Brookline, very close to
where I live and have lived, and I have never smelled
tobacco smoke there.

If Michio Kushi dies of heart disease or lung cancer,
we can suspect tobacco, and I presume (without direct
and immediate personal evidence) that the rumors are true,
but I won't be spreading them.

Maynard S. Clark