Counterpoint: This could be in part because men seek medical care less than women (source: https://www.icgi.org/do-men-go-to-the-doctor-less-than-women/#The_Data_A_Clear_Picture_of_Disparity), therefore when one does go the medical staff assumes it must be pretty serious, and this would reinforce that the self report study may not be accurate.
That said, it would still be extremely wrong for medical staff to assume that / downplay women who go because they're more likely to go, because then you'll be missing important cases in women, which may also explain why women have worse outcomes in medical care as well.
Overall the situation is shit because under the current system and culture it means men die more often from medical health issues and women die more from unnecessary malpractice and negligence.