No. A defrost programme is not a cooking programme, and a warm-looking cavity or moving fan does not prove that food has reached a safe cooking condition.
What the observation means
Defrosting suitability depends on the food, its packaging and the appliance instructions. A method intended for one small item may not be appropriate for a large joint or poultry. The oven may circulate air with little or no added heat. Treating the completion signal as a cooked-food signal confuses two different processes and can leave food inadequately prepared.
A useful next step
Follow the food producer's defrosting and cooking directions, using the oven programme only where those instructions and its manual permit it. Keep raw-food handling separate from cooked-food handling. If you selected defrost while expecting cooking heat, correct the programme choice rather than compensating with an arbitrary longer time. Do not taste partly prepared food to check whether the oven worked.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.