Irenaeus and the Text of Matthew 11:27 and Parallels

I was reading in Irenaeus’ Against Heresies last night and ran across this interesting little tidbit (you can read the text in context here):

For the Lord, revealing Himself to His disciples, that He Himself is the Word, who imparts knowledge of the Father, and reproving the Jews, who imagined that they, had [the knowledge of] God, while they nevertheless rejected His Word, through whom God is made known, declared, “No man knoweth the Son, but the Father; neither knoweth any man the Father, save the Son, and he to whom the Son has willed to reveal [Him].” Thus hath Matthew set it down, and Luke in like manner, and Mark the very same; for John omits this passage. They, however, who would be wiser than the apostles, write [the verse] in the following manner: “No man knew the Father, but the Son; nor the Son, but the Father, and he to whom the Son has willed to reveal [Him];” and they explain it as if the true God were known to none prior to our Lord’s advent; and that God who was announced by the prophets, they allege not to be the Father of Christ.

So, a few things there. First, I don’t see any variant related to tense change in Matt 11:27 or Luke 10:22 the NA27 apparatus. Next time I make a trip to the DTS library I’ll check the IGNTP Luke volume to see if anything shows up there. I wonder if we have this one in any of our manuscripts...

So why was he wrong about Mark? Mark doesn’t have the passage at all. He notes this about John. Was he working from memory and was just incorrect? Was this actually in his copy of Mark?

Note that it says that "They, however, who would be wiser than the apostles, write [the verse] in the following manner..." They write it in "the following manner", meaning they weren’t just misquoting, but had manuscripts that varied, if Irenaeus’ data can be trusted here.

Just some thoughts. Anyone out there ever see anything about this?