I don't think he did. I mean, it can be both. Maybe it was just something in Bowie's behaviour that pushed him over the edge, it's not hard to imagine...
I think I quoted these on another thread recently.
"'He was very ill with depression,' says Jo Slee. 'He wasn't really fit to go on the road, although I didn't know how ill he was until he really began to come apart at the seams.'
Jo won't say what Mozzer was depressed about.
'I really couldn't say,' she insists. 'Morrissey's suffered from depression all his life, more than anyone else I know. It's about repressed feelings, repressed emotions, repressed pain. It needs treatment. He was taking anti-depressants at the time because he was desperate to get out on the road, he really wanted to do the dates. But it was just too much for him.'"
(Dave Simpson, "Manchester's Answer To The H-Bomb", Uncut, 1998)
"'I have never spoken about this up until now because, in spite of everything, I do respect David,' he says. 'I simply have to play Star Man or Drive-in Saturday and I will forgive him for anything. But I left that tour because he put me under a lot of pressure, and I found it too exhausting.
'But then, Bowie is principally a business, and I can't imagine he would have telephoned his own mother without considering the career implications. David surrounded himself with very strong people, and that's the secret of his power: that everything he does will be seen in a certain light. But it certainly wasn't the greatest career move that I ever made, even though they gave 6,000 refunds in Manchester when I didn't appear - but I don't think you'd have read about that in the Manchester Evening News...'"
(Michael Bracewell, "Heaven Knows I'm Not Miserable Now", The Times, 1999)