We saw Karin pick up the gloves and touch the oil. We know that Spender used the gloves to put a hole in the brake system so that the oil would leak. So, why does the mechanic report that there's no oil on the gloves? Marc Bennett tells Karin the bad news casting some doubt on her theory and making her appear paranoid.
shareMaybe we're supposed to think that the whole thing is an elaborate plot on Spender's part to make her think she's just being paranoid--so that even the gloves were deliberately stained and left there for her to find. This theory stretches believability a bit, though, because Spender doesn't seem quite level-headed enough to think that deeply. But I would guess that was the screenwriter's intention.
shareWe know that Spender used the gloves to put a hole in the brake system so that the oil would leak.
The repeated lab tests proved that the stain was ink, NOT brake fluid!
shareAlan probably took the gloves stained with oil and hid them, and put the other ones in the car for Karin to find. When she was snooping around the car, he was watching her from outside. He expected her to find gloves with no oil. It was his way of scaring her. Just my opinion.
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JimHutton (1934-79) & ElleryQueen