Shaw was the subject of a poor challenge from defender Hector Moreno which has left the 20-year-old England international with a serious injury.
The former Southampton man is set for a lengthy time sidelined with a double leg fracture and van Gaal made his feelings clear on the matter during his post-match press conference.
“It was a bad tackle with two legs.
“Every word I say is always interpreted in the wrong way. It was in the 16 metre and it was a very bad tackle, with two legs.”
“He’s an 18-year-old boy who comes to Manchester and his first season is very difficult.
“Then he has a fantastic second season and this happens.
“When he came into the dressing room he had an oxygen mask and was crying.” Van Gaal added.
Man United took the lead at PSV Eindhoven when former player Memphis Depay netted late in the first-half but goals from Moreno and Luciano Narsingh helped Phillip Cocu’s side to victory.