Dear Nestor, all,
I understand your point, it also sounds like he didn't handle it very well. It's unfortunate, his postdoc is very good but new to the field so I think that he feels bad for missing the opportunity for him and is trying to find a working group which might still have a slot. Personally, I think the presentation should be very interesting, it's a little known and rather new channel with a lot of potential, so I think it would be good to have its exposure. We had discussed it among our WG and agreed that we could give him a slot -- I then also checked with Yoshi whether they were planning to after new slots opened (Samuel had told us that he had contacted WG5 first but there were no slots). He said they weren't but they could offer a swap if we wanted to have the talk. I don't know how he approached Yoshi, perhaps the request wasn't made in the best way, but I thought his email to us was OK. I think with the extra slots it would still be worth to accept the talk as an exception, as it would otherwise just penalise the postdoc and it wasn't his fault. But Guillaume, Rafał, please say if you don't agree.
Many thanks,
Daria