Matthew Oldfield said he used the patio door, when he went to check up the McCanns children. Kate in her first statement said:
Around 9.30pm was the time the interviewee should have gone to see her children, but her friend Matt (a member of the group) had just done a check in his apartment then gone to the interviewee's. He had entered the apartment by a glass sliding side door, that was always unlocked and once inside had not gone into the children's bedroom. He only looked through the door, and did not hear any noise. He went back to the restaurant and said that everything was fine.
At around 10pm, the interviewee went to check on the children. She went into the apartment by the side door, which was closed but not locked, as she said before.
http://www.mccannpjfiles.co.uk/PJ/KATE-MCCANN.htm
Bolded by me.
As for Gerald, this is the excerpt from his first statement:
In this way, at about 21.05 the witness came to the Club, entered the room using his respective key, the door being locked, went to his children's bedroom and checked that the twins were fine, as was Madeleine. "He then went to the WC" where he remained for a few moments, left, and bumped into a person he had played tennis with and who had a child's push chair, he was also British, he had a short conversation with him, "returning after that to the restaurant." At about 21.30 his friend Matt (member of the group) went to the apartment, where his children were and on his way went to the witness' apartment, entering by means of a glass sliding door that was always unlocked and was located laterally to the building.
Another excerpt from the same statement:
At about 22.00 it was his wife Kate who went to check on the children. She entered the apartment by the door using the key and saw immediately that the door to the children's bedroom was completely open, the window was also open, the blinds were raised and the curtains were drawn open.
Bolded also by me.
Okay, so they leave the sliding door unlocked, but they bother with the froont door and passing over the key? Weird.
But it's not the end. Here comes an excerpt from his second statement (BBM):
http://www.mccannpjfiles.co.uk/PJ/GERRY-MCCANN-10MAY.htm
Despite what he said in his previous statements, he states now and with certainty, that he left with KATE by the rear door which he consequently closed but did not lock given that that is only possible from the inside. Referring to the front door, while he is certain that it was closed it is unlikely that it was locked as [because] they had left by the rear door.
So then he and his wife used the key on an unlocked door, while checking on the kids?
At 21H05 MATHEW returned, the time at which the deponent left the table to go to check how his children were.
----- He followed the normal route up to the rear door, which being open he only had to move [slide] it, that being the way in which he entered [was entering] the lounge, he noted that the children's bedroom door was not ajar as he had left it but half-way open, which he thought strange, having then put together the thought of MADELEINE having got up to go to sleep in his bedroom so as to avoid the noise produced [created] by her siblings.
So now he changd his mind. He used the sliding patio door, not the front one. Undecided man he is. Also notice, he stated, he left the children bedroom door
ajar and found it half open. Didn't he said somewhere else he left that door nearly closed?
Half and hour later, without anything to signal [with no way to tell the time], it being 22h03, he turned to alert KATE that it was time for her to go to see the children. She immediately made her way to the apartment by the usual path, she having entered by the rear door.
He changed his mind also about Kate, Now he says, she also entered through the rear door. Why that change?