I was wondering if the mech had told the owner of the plane that the
hose
was in fact changed or not.

He said nothing. He didn't log the work as having been done, and he
didn't charge for it. Had my friend gone through the paperwork line by
line, he would have figured out that the hoses were not replaced. Of
course there was no requirement to replace them. It's perfectly legal
to fly around with 25 year old flexible hydraulic lines.

And no matter what the case may have been....it
is always the owner/pilots responsibility to check the maint. logs
for work
performed.

Yeah, sure. No matter what, you can make it the pilot's fault.
Personally, I think that if you instruct the mechanic to do something
at annual, he agrees to do it, and never mentions it again, you should
be able to trust that it got done. That's how one deals with
professionals.

Of course you can pretty reasonably argue that an A&P mechanic is NOT a
professional and should not be treated like one.

Michael