Shilton was selected by Ramsey for the match, walking out behind captain Martin Peters to earn his 15th cap. Aside from one incident, Shilton spent most of the game watching the opposing goalkeeper Jan Tomaszewski as he kept shot after shot out of Poland's net.  When the ball finally did get into the net it was at Shilton's end. Midway through the second half, Norman Hunter trod on the ball near the touchline and Poland broke away, with Grzegorz Lato feeding the ball across to the onrushing Jan Domarski.  As Domarski moved to hit the ball first time, Shilton got into position to attempt to block the shot. Domarski's drive, struck beyond defender Emlyn Hughes' challenge, was low and not well hit but was aimed inside the near goalpost and very close to Shilton. Shilton needed to deal with the shot but dived late, leaving the shot too close to his body, and Poland scored. Shilton later said he was trying to make "the perfect save" and forgot that his first priority was to keep the ball out of the net rather than make sure he held on to it. Shilton also claimed in his autobiography that this was the only mistake he made in his 125 caps for England.  England equalised swiftly through a penalty from Allan Clarke, with Shilton turning his back on the ball at the opposite end because he could not bear to look, but Tomaszewski's continued heroics kept England out to the final whistle, and England failed to qualify for the World Cup. Poland would go on to finish third in the competition.  As the season came to an end, Leicester reached the FA Cup semi-finals where Shilton was beaten -- in a replay after the initial game ended goalless -- by a lobbed volley from Liverpool's Kevin Keegan.

Answer this question "What was his mistake against Poland?" by extracting the answer from the text above.
Midway through the second half, Norman Hunter trod on the ball near the touchline and Poland broke away,