I think the partner resembles Chris Watts, which is most unfortunate for him, and likely to sway peoples opinions (those that have heard of CW, obviously!)
Statistically as we all know, harm to women is normally perpetrated by a male close to them so it's natural to suspect the partner when a woman goes missing. I think in this case though he wouldn't have had time to harm her, cover it up and raise the alarm with the police, and I assume he has an alibi which has been thoroughly checked by the police. He comes across as shifty in the interview but his whole life has been turned upside down and he knows he is being scrutinised - that would make me a bit nervy too. In fact, I probably wouldn't agree to do the interview in the first place - some of us are just not cut out for the public glare!
Some have mentioned on Twitter about Nicolas family not mentioning him - but then, maybe they don't like him? Maybe he's been a wanker to her? Who knows? Doesn't make him a murderer though. I think if my DD went missing I would keep my distance from her partner too till I knew 100% he'd been cleared - just because...statistics 🤷🏻♀️
All that being said, it's not nice the shit that's been written about him and I hope he's too busy consoling his girls to read it, but I think it's normal in these cases, and if I was in a similar situation I would fully expect my every word/move to be scrutinised until the case was resolved.