She should not seclude herself with him; only if there are witnesses - לא תתיחד עמו אלא בעדים
Summary:
The reason why the משנה rules אל תתייחד עמו בעדים in a case of מהיום אם מתי depends on whether she is מגורשת למפרע (so the reason is because of a ביאה לשם קידושין) or whether she is מגורשת סמוך למיתה (where the reason is because of גט ישן).
He said to him, I have witnesses but they are afraid of him for he is a strong man - אמר ליה אית לי סהדי ומסתפינו מיניה דאיניש אלמא הוא
Summary:
One can claim that the opposing litigant is a גבר אלים only if he can substantiate this claim; for instance that the עדים declare that they will not testify; in which case the גבר אלים must (can) use these עדים to validate his claim.
When she was speaking innocently - במסיחה לפי תומה
Summary:
The שפחה is believed מל"ת for her mistress but not the subject or her husband. By תרומה the subject is believed מל"ת. Generally מל"ת is believed by a דרבנן or שבויה and also by עדות אשה.