As he claimed in "Necessary Evil", Odo did indeed copy his hairdo from the scientist that worked on him.
This episode marks the first appearence of Dr. Mora Pol, Odo's surrogate father. He returns in the fifth season episode "The Begotten".
Goof: At Time Index 13:04 and several seconds after, you can clearly tell that the scenery in the background is a painting.
Goof: Sisko describes the death of his father to Dr. Mora. That same father is a recurring character later on in the series.
The significance of the pillar taken from the planet is never explained. It was a "red-herring" to mislead the audience into believing it was the cause of the random attacks.
Nitpick: When Odo is trapped by the forcefield, Dr. Mora says: "Dear God, what have I done?"... but Dr. Mora is a Bajoran and the Bajorans don't believe in God, but in the Prophets.
Nitpick: Odo is obviously injured and weakened by the force field they finally capture him in. Yet when he loses the strength to fight against it, he bothers to take on humanoid form. It would be much more logical to just melt and lie there in a puddle until he would feel better.
Nitpick: Sisko calls for a red alert and confines all non-essential personnel to their quarters. Several minutes later, Odo says that he will have the promenade cleared. Wouldn't the red alert taken care of that?
Dr Mora: (referring to the new life form) Any indication of intelligence?
Odo: Not unless you consider wanton destruction of the lab an indication of intelligence.
Dr Mora: Still having trouble with social integration.
Odo: I integrate as much as I want to.
Dr Mora: Define, 'as much as I want to.'
Odo: As much as I want to means as much as I want to!
Bashir: I prescribe rest, because it's hard for a doctor to go wrong with that one.
Odo: Humanoid death rituals are an interest of mine.
Quark: Death rituals...
Odo: Everybody needs a hobby.
Odo: Some species burn their dead, others pack them in blocks of ice... some even surround themselves with the company of family corpses. But the Ferengi ritual of chopping up their loved ones and selling them... I find that... irresistible.
Quark: I'm very busy.
Odo: What a fitting and distinguished way to honor the memory of great Ferengi entrepreneurs. I'm thinking of starting a collection. Putting up a display case in my office. There'll be a special space reserved just for you in there, Quark.
Sisko: Dax? Dr. Bashir released you from the Infirmary?
Jadzia: Dr. Bashir hid my clothes so I wouldn't leave. I had to sneak into my quarters, wearing a hospital gown that didn't quite close in the back.