Cloud wars: what happens when one vendor outs another?

Late last week, HP(s hpq) COO Bill Veghte made big news by announcing that Workday, the human resources SaaS provider that’s an industry darling, is moving from Amazon Web Services (s amzn) to HP Cloud.

This caught my eye because, 1: I didn’t realize Workday(S wday) was running on AWS and apparently was not alone in that; and, 2: It’s a pretty big win for HP Cloud, which is trying to gain credibility as a public cloud option — a realm that AWS rules.

The news came the final day of HP Discover and was reported here. I picked it up here, after sending an email to Workday for confirmation. Since it was a Sunday, Workday took some time to respond, but AWS sure didn’t: An Amazon (s AMZN) spokeswoman pinged to say that Workday remains a “happy AWS customer,” reiterating what Amazon CTO Werner Vogels had already tweeted:

When Workday got back to me — again, it was Father’s Day, so let’s cut them some slack — they also said they remain “a happy AWS customer.”

Update: And now HP itself weighs in with an emailed statement:

“During our HP Discover event, HP was very pleased to announce Workday as a customer for HP’s public cloud. However, we misstated the impact of that announcement on Workday’s relationship with Amazon Web Services. We apologize for the mistake,”

It’s always tricky when one company announces a big change by another company. Remember when Mirantis helpfully announced that PayPal was moving from the VMware(s vmw) stack to OpenStack? What PayPal(s ebay) actually said was a lot more nuanced, and I’d be willing to bet there is truth in both camps: That just as Paypal is using some VMware and some OpenStack, Workday will use a couple of clouds.

As big and efficient as AWS is, big customers would be nuts not to hedge their bets and pursue some sort of multi-cloud strategy. Luckily, Workday cofounder and co-CEO Aneel Bhusri and Vogels are both speaking at Structure this week, so we can ask them for ourselves.

This story was updated at 8:23 a.m. PDT with an HP statement.