How to approach colleague to address lack of teamwork behavior

Question

Background: we are a small hardware startup, with a management team of 3. Our day-to-day can be extremely high stress and frustrating, much of which stems from an inexperienced ceo. In my role, I address this by setting priorities based on the value of the work, and the toll it might take on my R&D team - the latter criteria is extremely important for us: the R&D team is in many cases one guy who has to do everything in a very short time. From past experience, this can lead to burnouts.

The problem: My issue concerns one colleague who is also in the management team, who recently has been more frequently externalizing their frustrations - they appear haggard, sends work messages at 3 am, and can't seem to hold focus.

Lately they also started behaving in a way that's caused some conflict:

• dropping in on colleagues to insist they are helped out with their prototype, even when explicitly told not to.
• while I was in the middle of speaking in a meeting with a colleague, they waved incessantly at me until I paid attention to them, to get me to check their text to me, which turned out to be a request to remind the ceo for some things that most certainly could have waited an hour.
• they missed an important meeting and accused another colleague of not sending the invite (which they did), and wouldn't drop it until explicitly told to drop it.
• on Thursday, i wanted to confirm that a recurring meeting will be postponed to next Tuesday, and they confirmed, but on Monday when asked to place the meeting on their schedule, said that their schedule is already full. When asked why, they said no decisions were made about the scheduling and his work has higher priority. Fyi, all of the other participants were off until Monday, and would not be able to respond until Monday. I was also off on that Monday, and had reached out for help to place the meeting on the schedule. Having had their confirmation for Tuesday, I was completely thrown by their reply, since I did not expect to have to deal with this on my day off.

How these incidents made me feel: This last incident feels like the last straw for me, and I feel the need to escalate and address these incidents, and this feeling that they are lacking a conscientiousness for their teammates, and generally lacking respect.

I don't know how best to do this. These are just my feelings, and how I've connected them to these events. I genuinely haven't worked out if my responses are rational or fair. It would be really great to have an outsider's opinion.

Goal: I would like to speak with mt colleague to forward these points:

1. I would like my colleague to see that their behavior is the cause of conflict. As of now, they view confrontations against them as random outbursts.
2. I would like my colleague to be more respectful and empathetic to their colleagues' workload and schedule.

Answer 1

• Speak with him either one-on-one or with just one third person.
• Keep your speaking-tone serious, but calm and emotionally neutral.
• Provide concrete examples. Describe consequences of his behavior. Concrete ones that cannot be disputed.
• Use examples where his behavior affected other colleges as well.
• Listen to his point of view. Keep calm even if it would make you angry.
• Have a short, concrete list of things you want him to do. You might not need to mention this list, but he might perhaps ask for it.
• Ask him if you can support him with the necessary changes.

Be prepared that his reaction (short term or long term) might not what you expect it to be.

Edit: Note that this is a quite "final" approach.

A softer approach would be to approach him sympathetically: "I have notice that you are very stressed..." Listen to what ever he wants to vent about. Perhaps point (sympathetically) to underlying issues. Ask him if he sees ways to solve some of his stressors. Make suggestions. This second approach would try to solve the problem by making an (emotional) ally out of an enemy. If he feels you are concerned for him, he will be more open when you tell him that some actions of his are stressing you.

If unsure, try this second approach first before trying the "hard" one.