They've already started building up angle as per the reported...

They've already started building up angle as per the reported true vertical depth for this flow interval 1782-1913m. 

Measured depth is 1845-2020m.

The formation wasn't mud-drilled at PV, but drilled with air/ mist. So u can get these sort of rates with air drilling when a gas zone is intersected.

Mist keeps the dust levels down & the air provides an under-balanced scenario. 

Basically with air-drilling they can stop anytime & flush the gas out of the blooie line as seen in the photo & record the flowrates via the larger dia orifice (3.5" in this case). They should also get a gas flare during each drill pipe connection.