They can't complain about trademarks if the file is the actual
unmodified upstream tarball: accuracy is an ultimate defence against
trademark claims. If it's been modified by removing stuff for
copyright reasons then you might have a problem, depending on how they
restrict use of the trademarks.
The tarball stands alone for this one; the rest of the source package
is irrelevant - if it's okay to distribute the stripped tarball alone,
then it's okay as part of the debian package too. Might be worth
asking them about it.