There are multiple positive and negative reports on Uber's financials in several publications, but the one(s) I've found most convincing are those put forth by Hubert Horan. He's written a 14+ part series [1] on both the financials and the general reporting surrounding Uber, along with an academic paper [2]. He makes compelling points, and is pretty damn thorough.

It's impossible to know for sure, but it may have swayed his decision.

[1] - https://www.nakedcapitalism.com/2016/11/can-uber-ever-delive... (several more on the site)

[2] - https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2933177