YOU SAID:

He probably had no idea what they were really doing, perhaps too excited about working with such unusual samples to notice anything suspicious.

INTO JAPANESE

おそらく彼は、彼らが実際に何をしているのかまったく分かりませんでした。おそらく、このような珍しいサンプルを扱うことに興奮しすぎて、何か不審な点に気づくことができなかったのでしょう。

BACK INTO ENGLISH

Perhaps he had no idea what they were actually doing. Perhaps they were too excited to work with such an unusual sample to notice anything suspicious.

INTO JAPANESE

おそらく彼は、彼らが実際に何をしているのか全く分かりませんでした。おそらく彼らは、このような珍しいサンプルを扱うことに興奮しすぎて、何か不審な点に気づくことができなかったのでしょう。

BACK INTO ENGLISH

Perhaps he had no idea what they were actually doing. Perhaps they were too excited to work with such an unusual sample to notice anything suspicious.