On 6th, TV Daily had a phone interview with Kim Jungkwan PD and he said, "First, Taeyeon is faultless regarding this matter. The other news articles which claimed 'Taeyeon started laughing while reading a letter from a listener' is wrong".
Kim Jungkwan PD continued, "I am very disconcerted regarding this incident, because it shouldn't have become this serious. There was a reason to why she laughed, but she didn't laugh after reading a letter from a listener or the typo on the script. At that time, there was a circumstance in the studio; Taeyeon burst out laughing because of that circumstance".
Also, he added, "Unfortunately, I am unable to explain to you what that circumstance was because it is an internal problem. At that time, Taeyeon apologized three times and I think it is wrong for her to apologize again during future radio session, when she is not at fault".
Finally, he expressed his frustration, "It is unfortunate to see the portion of media taking advantage of this matter and write malicious news articles that read 'After reading a story about how someone failed a test for college, Taeyeon laughed at it'".
translated by cathode @ ssf
Hope it's okay to post a separate entry for this, mods. A PD spoke out, so I figured it would clear things up.
He seems pretty protective of Taeyeon, lol.