loose fuse, dead battery?

I found that I put a fuse in the fuse holder wrong,one of the male tabs from the fuse was between the fuse holder insulation and the female terminal,could this cause a dead battery?

That depends on what the fuse is for.  If it is for an aftermarket accessory, amp lights etc..   No it will not cause a dead battery.  If it is in the charging circuit of your vehicle then yes it could cause a dead battery.

This fuse was one of the 2 main power fuses for a combo remote start/alarm unit(Crimestopper 2011).

I do not see how that could drain your battery. 

That is the only thing I seen wrong with the install,The owner said it was dead a couple days after sitting a couple of days.The battery was only 2 months old.

What vehicle is this? After charging or replacing battery, diconnect neg. terminal and set to 10 or 20 amps place black lead of DMM on neg terminal and red lead to disconnected ground lead. Close the doors, wait about 1 minute and then check the current draw, on any thing bar a late BMW/Mec/Benz/Caddy it should be about 30-40 milliamps. Voltage should be 12.6, also if you are able to do a drop test, ie starter motor turning over for 10 seconds without firing up,voltage should not drop below 10 vo,lts. If it does your battery is a gonner! On starting the voltage at the batterhy should read 13.4 or more, slightly lower with a diesel, again if not your alternator is a gonner!

this was installed in a 2005 aztek,the owner also called me the day after the install and said the car won't start and she smells gas,she was close by so I went there to see what was up.When I looked under the car gas was pouring out of the top of the gas tank with the key on,I told her it was prolly a broken gas line but definitly not a remote start issue.I later found out it was a broken clamp on a fuel line over the tank.