No, printed leaflets are not safer than QR-codes containing the password and the link. The latter may even add an extra layer of compliance since visitors and referrers of the webpage can be monitored.
Scenario 1
Dr Chan receives a leaflet by a sales-representative just before lunch. He takes the printed Symposium Highlight to the canteen for reading. However, he meets a colleague and when they leave together, Dr Chan accidentally leaves the print behind. The next user of the table is a patient who finds the leaflet and takes it home because she is interested in information about her disease.
Scenario 2
Dr Lee is speaking during a big congress and takes a printed leaflet, which he has just received from a sales professional, to the airport for reading during his flight. On board the plane he meets a patient advocate who is travelling to the same meeting. The patient is interested in reading the leaflet and asks Dr Lee to share the leaflet with him.
These scenarios are unlikely, and this is exactly how unlikely it is that QR-codes are obtained by members of the lay-public: QR-codes are printed on the leaflets which are only provided to HCPs.