В этом случае может быть презумпция нелегального нахождения на территории Шенгена:
Schengen Borders Code
Article 12
Presumption as regards fulfilment of conditions of duration of stay
1. If the travel document of a third-country national does not bear an entry stamp, the competent national authorities may presume that the holder does not fulfil, or no longer fulfils, the conditions of duration of stay applicable within the Member State concerned.
2. The presumption referred to in paragraph 1 may be rebutted where the third-country national provides, by any means, credible evidence, such as transport tickets or proof of his or her presence outside the territory of the Member States, that he or she has respected the conditions relating to the duration of a short stay.