Darren Pratley's first-half header from Marc Tierney's cross had given Wanderers the lead.
But David Wheater then gave away a penalty in the early stages of the second half to give Blackman the chance to equalise, which he duly converted to earn the Royals a point.
Freedman said: "I felt that it was a good match and we were outstanding in the first 45 minutes.
"But fair play to Reading. They looked like a Premier League side today and they counter-attacked us really well.
"I will be amazed if they aren't in the top six. We've played a really top team there and there wasn't much in it.
Reading manager Nigel Adkins, meanwhile, defended the referee's performance despite two further penalty decisions not going their way.