Again this is wrong. The HK bar observations (the first document I read on the matter) don't comment on whether the HK extradition bill are inline with extradition treaties of other jurisdictions. Neither does their observations say that the bill is going to result in people being taken. They specifically point out weaknesses in the bill that could lead to abuse. Note that 1) they're correct on most points, 2) they are actually making points not made by the protestors, 3) the abuses that they cite in the bill exist in the US Canada bill too.

The US Canada extradition treaty is only 39 pages. You'll notice that one of the key criticisms of the HK Bar association is they don't like the idea that cases can be initiated by the CEO of HK without needing to go through the legislative Council. In Canada, the requests go through the DoJ, which ultimately report to the Prime Minister and also do not go through any vetting by the opposition party. These HK bar lawyers would also be against the Canada US extradition treaty on this point.

I'm not going to go through all points but you'll notice point 18 they specifically point out that it isn't so much that they disagree with the principle but believe strongly that the execution will be tainted. But you could say that about the US Canada extradition bill too.

Again, highly recommend everyone interested read the actual material instead of relying on Facebook/FT/CNN/etc. There's a reason that few lawyers are against the principles of the bill. Most are worried that it will be amended in the future to drop protections or have the details mixed up: ie they think Chinese crimes committed in HK fall under this bill when they don't - only crimes that are crimes in both jurisdictions and of those only a subset can be considered under the bill. And the wording is a rip off of what we have in the US Canada extradition bill.