The situation may be somewhat different under a national system like the UK NHS, but here in the U.S., the main issue I foresee is leas reliability than accountability.
A doctor in the U.S. who makes a random mistake carries mandatory malpractice insurance that will cover any liability for injury with relatively little pushback to the patient/inconvenience to the Doctor. Repeated patterns of mistakes by individual doctors cause less inconvenience, i.e. higher premiums, more pushback on claims, and possibly loss of insurance/ability to practice. This finely tuned actuarial system gives doctors reasonable security while also incentivizing them to keep up a basic level of quality to their work.
A billion dollar venture-backed company is going to have a whole different set of incentives, namely to use their much larger legal resources to fight as many lawsuits as possible ab initio in order to maximize profitability. Given how tort/negligence law and punitive damages work in the U.S., the company could be on the hook for billions of dollars from just a single bad suit, let alone a continued pattern of them.
Now they are probably already heavily lobbying lawmakers to enact regs to shield themselves from liability, and drawing up contractual language for click-through licenses that patients will never read that purport to absolve them of any liability for mistakes. But this has the makings of massive PR blowback and continued litigation as stories of people being harmed with no recourse start piling up.