Neil deGrasse Tyson, the well-known astrophysicist, TV host, and general science enthusiast (whose shtick is sometimes obnoxious and easily criticized), has been accused of sexual misbehavior by three different women. He addressed the allegations in a Facebook post on Saturday.

"In any claim, evidence matters," wrote Tyson. "Evidence always matters."

He's right. We should not naively presume that all claims are true, absent corroboration or supporting evidence. The public should withhold further judgement until Fox and National Geographic—Tyson's employers—complete their investigations.

In the meantime, it's helpful to consider each accusation separately, because they are quite different. The most serious of the incidents allegedly occurred in the early 1980s, while Tyson was a graduate student: A classmate whom Tyson briefly dated claims he drugged and raped her. Here was what Tyson had to say about it:

According to her blog posts, the drug and rape allegation comes from an assumption of what happened to her during a night that she cannot remember. It is as though a false memory had been implanted, which, because it never actually happened, had to be remembered as an evening she doesn't remember. Nor does she remember waking up the next morning and going to the office. I kept a record of everything she posted, in case her stories morphed over time. So this is sad, which, for me, defies explanation.

It's very hard to know who is telling the truth here. As with the allegations against Brett Kavanaugh, a great deal of time has passed, and distant memories are tricky things. (At least one of the allegations against Kavanaugh seems unlikely to be accurate, for instance.) We may never know more than we know now. If this accuser has some way to corroborate her account, she should do that. Otherwise, it seems unfair to obligate Tyson to disprove a claim from so long ago.

Tyson's second accuser, a colleague at a conference in 2009, made a much less serious claim: She said she asked him to pose for a picture, and he took notice of a tattoo of the solar system on her arm. He was curious whether Pluto was part of the tattoo, and allegedly searched "up her dress." But she was wearing a sleeveless dress—Pluto would have been near the shoulder, perhaps under a strap. I presume Tyson interacts with thousands of fans each year. Slightly misjudging one such fan's comfort level after a photo request doesn't seem like much of a scandal, in this context.

The third accusation is the one that really requires proper investigation: A former assistant of Tyson's says he made her feel uncomfortable, accused her of being "distracting," and took actions that implied romantic interest. Tyson admits that he invited her over for wine and cheese—something he does often for visitors, he claims—which she accepted.

"Afterwards, she came into my office to told me she was creeped out by the wine & cheese evening," Tyson wrote. "She viewed the invite as an attempt to seduce her, even though she sat across the wine & cheese table from me, and all conversation had been in the same vein as all other conversations we ever had."

Tyson admitted he offered her a special handshake he had learned from a Native American elder, which involved taking the pulse of the other person.

"I've never forgotten that handshake, and I save it in appreciation of people with whom I've developed new friendships," wrote Tyson. He says he apologized to the assistant, she accepted his apology, and then quit the job.

Tyson may have been too friendly with this assistant. (I wonder, though, how many people who find the wine-and-cheese invite creepy also think the Pence Rule is an affront to gender equality.) He may have harassed this employee, or made work uncomfortable for her. He may also just be a demanding and difficult-to-work-with major celebrity. Perhaps he did nothing wrong at all. His employers should certainly look into it.

In the meantime, there is no need to preemptively declare him a sex jerk. Despite what the more militant members of the #MeToo movement seem to think, automatically believing accusations is bad practice in a world where not all encounters are black and white.