.Holden earned a point but was denied a first victory in eight outings by the Posh, who ended the campaign in ninth place, six clear of their hosts.
Dominic Poleon put Oldham in front with a neat ninth-minute header but despite losing Jonathan Edwards to a red card after 67 minutes for a foul on James Wilson, the visitors responded to take a deserved share of the spoils.
Michael Bostwick hit his sixth goal of the season in the 76th minute, arrowing a drive home after a corner kick was only half-cleared into his path.
The result left Holden – in charge until the end of the season – focusing on ways Oldham can improve in League One next term.
“We started the game very well, passing it around before we started playing too straight and too slow,” Holden said.
“There was a lull after half-time before the game got going again and we played some good stuff.
“A point each was probably right. It was symptomatic of the season in that we gave a soft goal away.
“There have been circumstances we have had to deal with but we will look back on what we have done well and what we have not done well in the next couple of days.
“I am sure there will be meetings taking place and we will be working out how we can progress the club.”
Peterborough boss Dave Roberston is in a similar position to Holden, not knowing whether he will be kept on as manager for next season.
He was left pleased with the response his side came up with to the adversity they found themselves in, most notably when midfielder Erhun Oztumer went off with a nasty-looking injury in the first half.
“It looks like he (Oztumer) will have to go to hospital to get some stitches in his leg,” Robertson said.
“We were worried at first it may have been a break and a longer-term one. He has been magnificent for us and luckily enough he just needs stitches.
“We had two of our in-form players go down with injuries in the first half. Gabriel Zakuani rolled his ankle as well, so that will be four weeks. They will both be back and strong to play a big part in next year’s group.
“We have tinkered with the players over the last few games and the formations, to work on our playing style ready for next year.
“But the most important thing that has come through is the character in the group, which has shone as it did here.
“Michael Bostwick has six goals now and he is a goal scoring sensation. We know he has goals in him and he has a really strong mentality.
“If there is anyone in the team who can go to the very top, he is one of them.”