Hmm, bullshit? Need some opinions

Alright so yesterday I sold a friend two 2mg Klonopins. He consumed them and then went to the court house to pay off his court fines. (Stupid idea on his part I know)

Well, there was a huge line to wait in, so he sat down in a chair and ended up falling asleep. (Klonopin has a very sedative effect and will make you drowsy.) When he woke up, there were 3 police officers standing in front of him. They then took him to the hospital, got him drug tested, found out he was on Klonopin and made him spend a night in jail.

Now, at the hospital the doctors told him that he was allergic to Klonopin and that's why he passed out. He is now convinced that he is allergic to this pill.

Now the point to my story:

I think that the doctors are completely lieing to him, and he is not allergic to the drug. I think they told him that simply to scare him from ever abusing it again.

My reason(s) for this theory is the fact that he has taken Xanax and Lorazepam many MANY times, in which both fall into the exact same drug-class as Klonopin. (Benzodiazepines) Now yes, they do differ slightly, but I think if he would have a reaction to Klonopin, he would also have a reaction to Xanax and/or Lorazepam..

So, what are you're guys' thoughts?