that's a thing i encountered on various entity types. the usage of count isn't obvious in the json results. in the xml results the count is an attribute of a array element which makes it obvious to which list it belongs. in the json file this isn't obvious and when an entity has multiple arrays the count value is probably not defined.

in the new ws the count for tags was added. therefore a couple of entity types have at least two arrays in them. here are some examples where i encountered this problem:

artist
new json result
old json result
new xml result
old xml result

release-group
new json result
old json result
new xml result
old xml result

release
new json result
old json result
new xml result
old xml result

recording
new json result
old json result
new xml result
old xml result

label
new json result
old json result
new xml result
old xml result