@justme88,
It could be quite rude of him to:
- be sorting out a family crisis, and then say 'hold on...I know you're angry, let me just take this call...
- at work, in a sales meeting and say 'can we put the meeting on hold, have to take this call
Alternatively, he could be doing something that has to go to a timetable or things get difficult
Or he could be doing something that requires both time & focus
Or...any number of things.
Why is it a problem to have a one off 'I can't talk right now, but I can I call you tomorrow'? Or even multiple such cases?
Generally speaking, such reactions usually stem from insecurities. In relation to self esteem, a lot of people don't realise that it can be situation specific:
- you can value your skills in a specific area, even while you can be down on yourself about skills in another area
- you can move assuredly through one area, while treading cautiously in another
+
...that's esteem to do with your skills. Then there is esteem to do with your principles, and esteem to do with your character. All of them make up 'who you are'.
Short version - even though you may have high self esteem, it seems that it is lower in this area.