Javascript memory profiler for Firefox

I haven't tried the Sofware verify tools, but Mozilla has tools that track overall memory consumed by firefox for the purpose of stemming leaks:

http://www.mozilla.org/performance/tools.html

and:

https://wiki.mozilla.org/Performance:Leak_Tools

There's also this guy saying to avoid large arrays in the context of closures, towards article bottom

http://ajax.sys-con.com/node/352585

I think JavaScript Memory Validator from Software Verification Limited can help you, it has allocations view, objects view, generations view, etc. It's not free but you can use the evaluation version to check your coworker's code. They also have a Performance and Coverage Validators...