I believe it to be true, and I'm pretty sure that there is a form that is signed when you purchase a used homebuilt that states that the a/c is homebuilt and does not meet any cert requirments, and you are using it at you own risk.
I can't believe that an A&P or IA would sign off a homebuilt aircraft!!!! I don't think you would find many in Canada that would. I know I won't. I work on quite a few homebuilts, and always tell the owners that they have to sign it themselves, I wouldn't have my name in the log, unless it was as a pilot.