Jean, who has two games earlier in the season with 18 rebounds, had 19 defensive rebounds and three offensive boards en route to the record night.
Zach Pickelman added 19 points and Tanner Judrna (17) and James Peters (10) all scored in double figures for the Cowboys.
HSU led 37-31 at the half and were never seriously threatened in the second half. A late surge put the game into double figures. Lance Hrncir had 14 points and Kevin Deans added 12 for Schreiner.
The Cowboys improved to 12-8 on the year and to 11-6 in conference play. Schreiner fell to 3-15 overall and 3-13 in league play. HSU hosts Texas Lutheran on Saturday at 3 p.m.