oh no this remco seems to be in distress :( https://www.tumblr.com/23mco/795936828285960192
You are absolutely correct, this beautiful golden Remco is feeling both angry and upset! Remcos are one of the more emotional species, experiencing more intense highs and lows than for example the calm and serene Neilson. The adult Remco shown is pictured in the act of attacking a water bottle during supervised outdoor time.
This behaviour may result from multiple reasons. He may be engaged in a hunt which has ended badly, with his prey escaping. He might have been chased away from his intended prey by a more aggressive Remco, or by a member of another species. It's also possible that he is struggling with the water bottle itself. Although most Remcos can learn to drink bottled water, a few cannot and prefer to lap from a bowl, as is the case for a substantial percentage of Mathieus.
Whilst it is always upsetting to see our beloved companions unhappy, this distressed Remco is lashing out at an inanimate object rather than another species or his keeper. This is praise-worthy behaviour! It is not always possible to prevent your Remco having emotional outbursts, but water bottles and enrichment toys are replacable and do not feel any pain.
As he calms down, this Remco will become cold and drained once his emotions run their course. Instead of returning him to his travel enclosure to self-soothe as you would a Mathieu, sit together with him in a safe, enclosed area (perhaps the back of your car). He will likely be vigorously 'telling' you about why he is so angry, but once he is no longer uttering sharp yaps but more plaintive ones, offer a favourite treat along with lots of cuddles, and plenty of praise for how well he managed his emotions.
This helps reinforce the positive behaviour you want to see more of, while reminding your Remco of how much you love him. As the two of you get used to handling his emotional outbursts, this 'post-anger' drop will lessen in intensity, but will never entirely disappear. Once your Remco is calm, he can then be returned to his travel enclosure with a favourite comfort item for the journey home, but don't be surprised if after this intense experience he takes the opportunity to have a nap!