when seeing other's MEs' WS as a ME, pointers are locked

[matiroy]

ex.: https://mosaic.ought.org/w/d042460f-e3c1-4475-9b99-59efc596dac5

it makes it more confusing for ME's to know if they can actually open the pointers (also for analysts reviewing the trees potentially)

important? not really since it seems we're moving away from having the MEs' use the scratchpad, so they might just come to consult the tree view and Google Doc

issue raised by Liam

more details: https://app.slack.com/client/T3L8K3NMT/DMK0R1F32/thread/DMK0R1F32-1566618284.004200